-
Notifications
You must be signed in to change notification settings - Fork 1.8k
Expand file tree
/
Copy pathbuffer.html
More file actions
2818 lines (2623 loc) · 214 KB
/
Copy pathbuffer.html
File metadata and controls
2818 lines (2623 loc) · 214 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<!DOCTYPE html><html lang="en"><head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Buffer | Node.js v12.10.0 Documentation</title>
<link rel="stylesheet" href="data:text/css;base64,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">
<link rel="stylesheet" href="data:text/css;base64,/*--------------------- Layout and Typography ----------------------------*/
html {
  font-size: 1rem;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-variant-ligatures: none;
          font-variant-ligatures: none;
}

* {
  box-sizing: border-box;
}

body {
  font-family: "Lato", "Lucida Grande", "Lucida Sans Unicode", "Lucida Sans", Verdana, Tahoma, sans-serif;
  margin: 0;
  padding: 0;
  color: #333;
  background: #fff;
}

h1 { font-size: 2.5rem }
h2 { font-size: 2rem }
h3 { font-size: 1.75rem }
h4 { font-size: 1.5rem }
h5 { font-size: 1.25rem }
h6 { font-size: 1rem }

h1, h2, h3, h4, h5, h6 {
  margin: 1.5rem 0 1rem;
  text-rendering: optimizeLegibility;
  font-weight: 700;
  position: relative;
}

pre, tt, code, .pre, span.type, a.type {
  font-family: SFMono-Regular, Menlo, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: .9em;
}

#content {
  position: relative;
}

a, a:link, a:active {
  color: #43853d;
  text-decoration: none;
  border-radius: 2px;
  padding: 1px 3px;
}

a:hover, a:focus {
  color: #fff;
  background-color: #43853d;
  outline: none;
}

strong {
  font-weight: 700;
}

code a:hover {
  background: none;
}

em code {
  font-style: normal;
}

#changelog #gtoc {
  display: none;
}

#gtoc {
  margin-top: .5rem;
  margin-bottom: 1rem;
}

#gtoc ul {
  list-style: none;
  margin-left: 0;
  line-height: 1.5rem;
}

#gtoc > ul > li {
  display: inline;
  border-right: 1px #000 solid;
  margin-right: 0.4rem;
  padding-right: 0.4rem;
}

#gtoc > ul > li:last-child {
  border-right: none;
  margin-right: 0;
  padding-right: 0;
}

li.version-picker {
  position: relative;
}

li.version-picker:hover > a {
  border-radius: 2px 2px 0 0;
}

li.version-picker:hover > ol {
  display: block;
  z-index: 1;
}

li.version-picker a span {
  font-size: .7rem;
}

ol.version-picker {
  background: #fff;
  border: 1px #43853d solid;
  border-radius: 0 0 2px 2px;
  display: none;
  list-style: none;
  position: absolute;
  right: 0;
  top: 1.25rem;
  width: 100%;
}

#gtoc ol.version-picker li {
  display: block;
  border-right: 0;
  margin-right: 0;
}

ol.version-picker li a {
  border-radius: 0;
  display: block;
  margin: 0;
  padding: .1rem;
  padding-left: 1rem;
}

ol.version-picker li:last-child a {
  border-bottom-right-radius: 1px;
  border-bottom-left-radius: 1px;
}

.line {
  width: calc(100% - 1rem);
  display: block;
  padding-bottom: 1px;
}

.api_stability {
  color: white !important;
  margin: 0 0 1rem 0;
  font-family: "Lato", "Lucida Grande", "Lucida Sans Unicode", "Lucida Sans", Verdana, Tahoma, sans-serif;
  padding: 1rem;
  line-height: 1.5;
}

.api_stability * {
  color: white !important;
}

.api_stability a {
  text-decoration: underline;
}

.api_stability a:hover, .api_stability a:active, .api_stability a:focus {
  background: rgba(255, 255, 255, .4);
}

.api_stability a code {
  background: none;
}

.api_stability_0 {
  background-color: #D60027;
}

.api_stability_1 {
  background-color: #EC5315;
}

.api_stability_2 {
  background-color: #4EBA0F;
}

.api_metadata {
  font-size: .85rem;
  margin-bottom: 1rem;
}

.api_metadata span {
  margin-right: 1rem;
}

.api_metadata span:last-child {
  margin-right: 0px;
}

ul.plain {
  list-style: none;
}

abbr {
  border-bottom: 1px dotted #454545;
}

p {
  text-rendering: optimizeLegibility;
  margin: 0 0 1.125rem 0;
  line-height: 1.5;
}

#apicontent > *:last-child {
  margin-bottom: 0;
  padding-bottom: 2rem;
}

table {
  border-collapse: collapse;
  margin: 0 0 1.5rem 0;
}

th, td {
  border: 1px solid #aaa;
  padding: .75rem 1rem .75rem 1rem;
  vertical-align: top;
}

th {
  text-align:left;
}

ol, ul, dl {
  margin: 0 0 .6rem 0;
  padding: 0;
}

ol ul, ol ol, ol dl, ul ul, ul ol, ul dl, dl ul, dl ol, dl dl {
  margin-bottom: 0;
}

ul, ol {
  margin-left: 2rem;
}

dl dt {
  position: relative;
  margin: 1.5rem 0 0;
}

dl dd {
  position: relative;
  margin: 0 1rem 0;
}

dd + dt.pre {
  margin-top: 1.6rem;
}

#apicontent {
  padding-top: 1rem;
}

#apicontent .line {
  width: calc(50% - 1rem);
  margin: 1rem 1rem .95rem;
  background-color: #ccc;
}

h2 + h2 {
  margin: 0 0 .5rem;
}

h3 + h3 {
  margin: 0 0 .5rem;
}

h2, h3, h4, h5 {
  position: relative;
  padding-right: 40px;
}

.srclink {
  float: right;
  font-size: smaller;
}

h1 span, h2 span, h3 span, h4 span {
  position: absolute;
  display: block;
  top: 0;
  right: 0;
}

h1 span:hover, h2 span:hover, h3 span:hover, h4 span:hover {
  opacity: 1;
}

h1 span a, h2 span a, h3 span a, h4 span a {
  color: #000;
  text-decoration: none;
  font-weight: bold;
}

pre, tt, code {
  line-height: 1.5rem;
  margin: 0; padding: 0;
}

.pre {
  line-height: 1.5rem;
}

pre {
  padding: 1rem;
  vertical-align: top;
  background: #f2f2f2;
  margin: 1rem;
  overflow-x: auto;
}

pre > code {
  padding: 0;
}

pre + h3 {
  margin-top: 2.225rem;
}

code.pre {
  white-space: pre;
}

#intro {
  margin-top: 1.25rem;
  margin-left: 1rem;
}

#intro a {
  color: #ddd;
  font-weight: bold;
}

hr {
  background: none;
  border: medium none;
  border-bottom: 1px solid #7a7a7a;
  margin: 0 0 1rem 0;
}

#toc h2 {
  margin-top: 0;
  margin: 1.5rem 0;
}

#toc p {
  margin: 0;
}

#toc ul a {
  text-decoration:none;
}

#toc ul li {
  margin-bottom: .666rem;
  list-style: square outside;
}

#toc li > ul {
  margin-top: .666rem;
}

#toc .stability_0::after {
  background-color: #d50027;
  color: #fff;
  content: "deprecated";
  margin-left: .25rem;
  padding: 1px 3px;
  border-radius: 3px;
}

#apicontent li {
  margin-bottom: .5rem;
}

#apicontent li:last-child {
  margin-bottom: 0;
}

tt, code {
  color: #040404;
  background-color: #f2f2f2;
  border-radius: 2px;
  padding: 1px 3px;
}

.api_stability code {
  background: rgba(0, 0, 0, .1);
}

a code {
  color: inherit;
  background: inherit;
  padding: 0;
}

.type {
  line-height: 1.5rem;
}

#column1.interior {
  margin-left: 234px;
  padding: 0 2rem;
  -webkit-padding-start: 1.5rem;
}

#column2.interior {
  width: 234px;
  background: #333;
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  overflow-x: hidden;
  overflow-y: scroll;
}

#column2 ul {
  list-style: none;
  margin: .9rem 0 .5rem;
  background: #333;
}

#column2 > :first-child {
  margin: 1.25rem;
  font-size: 1.5rem;
}

#column2 > ul:nth-child(2) {
  margin: 1.25rem 0 .5rem;
}

#column2 > ul:last-child {
  margin: .9rem 0 1.25rem;
}

#column2 ul li {
  padding-left: 1.25rem;
  margin-bottom: .5rem;
  padding-bottom: .5rem;
}

#column2 .line {
  margin: 0 .5rem;
  background-color: #707070;
}

#column2 ul li:last-child {
  margin-bottom: 0;
}

#column2 ul li a {
  color: #ccc;
  border-radius: 0;
}

#column2 ul li a.active, #column2 ul li a.active:hover,
#column2 ul li a.active:focus {
  color: #43853d;
  border-radius: 0;
  border-bottom: 1px solid #43853d;
  background: none;
}

#intro a:hover, #intro a:focus,
#column2 ul li a:hover, #column2 ul li a:focus {
  color: #fff;
  background: none;
}

span > .mark, span > .mark:visited {
  color: #707070;
  position: absolute;
  top: 0px;
  right: 0px;
}

span > .mark:hover, span > .mark:focus, span > .mark:active {
  color: #43853d;
  background: none;
}

th > *:last-child, td > *:last-child {
  margin-bottom: 0;
}

.changelog > summary {
  margin: .5rem 0;
  padding: .5rem 0;
  cursor: pointer;
}

/* simpler clearfix */
.clearfix:after {
  content: ".";
  display: block;
  height: 0;
  clear: both;
  visibility: hidden;
}

.github_icon {
  vertical-align: middle;
  margin: -2px 3px 0 0;
}

@media only screen and (max-width: 1024px) {
  #content {
    overflow: visible;
  }
  #column1.interior {
    margin-left: 0;
    padding-left: .5rem;
    padding-right: .5rem;
    width: auto;
    overflow-y: visible;
  }
  #column2 {
    display: none;
  }
}

@media print {
  html {
    height: auto;
    font-size: 0.75em;
  }
  #column2.interior {
    display: none;
  }
  #column1.interior {
    margin-left: 0px;
    padding: 0px;
    overflow-y: auto;
  }
  .api_metadata,
  #toc,
  .srclink,
  #gtoc,
  .mark {
    display: none;
  }
  h1 {
    font-size: 2rem;
  }
  h2 {
    font-size: 1.75rem;
  }
  h3 {
    font-size: 1.5rem;
  }
  h4 {
    font-size: 1.3rem;
  }
  h5 {
    font-size: 1.2rem;
  }
  h6 {
    font-size: 1.1rem;
  }
  .api_stability {
    display: inline-block;
  }
  .api_stability a {
    text-decoration: none;
  }
  a {
    color: inherit;
  }
  #apicontent {
    overflow: hidden;
  }
}
">
<link rel="stylesheet" href="data:text/css;base64,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">
<link rel="canonical" href="https://nodejs.org/api/buffer.html">
</head>
<body class="alt apidoc" id="api-section-buffer">
<div id="content" class="clearfix">
<div id="column2" class="interior">
<div id="intro" class="interior">
<a href="https://nodejs.org/" title="Go back to the home page">
Node.js
</a>
</div>
<ul>
<li><a href="https://nodejs.org/api/documentation.html" class="nav-documentation">About these Docs</a></li>
<li><a href="https://nodejs.org/api/synopsis.html" class="nav-synopsis">Usage & Example</a></li>
</ul>
<div class="line"></div>
<ul>
<li><a href="https://nodejs.org/api/assert.html" class="nav-assert">Assertion Testing</a></li>
<li><a href="https://nodejs.org/api/async_hooks.html" class="nav-async_hooks">Async Hooks</a></li>
<li><a href="https://nodejs.org/api/buffer.html" class="nav-buffer active">Buffer</a></li>
<li><a href="https://nodejs.org/api/addons.html" class="nav-addons">C++ Addons</a></li>
<li><a href="https://nodejs.org/api/n-api.html" class="nav-n-api">C/C++ Addons - N-API</a></li>
<li><a href="https://nodejs.org/api/child_process.html" class="nav-child_process">Child Processes</a></li>
<li><a href="https://nodejs.org/api/cluster.html" class="nav-cluster">Cluster</a></li>
<li><a href="https://nodejs.org/api/cli.html" class="nav-cli">Command Line Options</a></li>
<li><a href="https://nodejs.org/api/console.html" class="nav-console">Console</a></li>
<li><a href="https://nodejs.org/api/crypto.html" class="nav-crypto">Crypto</a></li>
<li><a href="https://nodejs.org/api/debugger.html" class="nav-debugger">Debugger</a></li>
<li><a href="https://nodejs.org/api/deprecations.html" class="nav-deprecations">Deprecated APIs</a></li>
<li><a href="https://nodejs.org/api/dns.html" class="nav-dns">DNS</a></li>
<li><a href="https://nodejs.org/api/domain.html" class="nav-domain">Domain</a></li>
<li><a href="https://nodejs.org/api/esm.html" class="nav-esm">ECMAScript Modules</a></li>
<li><a href="https://nodejs.org/api/errors.html" class="nav-errors">Errors</a></li>
<li><a href="https://nodejs.org/api/events.html" class="nav-events">Events</a></li>
<li><a href="https://nodejs.org/api/fs.html" class="nav-fs">File System</a></li>
<li><a href="https://nodejs.org/api/globals.html" class="nav-globals">Globals</a></li>
<li><a href="https://nodejs.org/api/http.html" class="nav-http">HTTP</a></li>
<li><a href="https://nodejs.org/api/http2.html" class="nav-http2">HTTP/2</a></li>
<li><a href="https://nodejs.org/api/https.html" class="nav-https">HTTPS</a></li>
<li><a href="https://nodejs.org/api/inspector.html" class="nav-inspector">Inspector</a></li>
<li><a href="https://nodejs.org/api/intl.html" class="nav-intl">Internationalization</a></li>
<li><a href="https://nodejs.org/api/modules.html" class="nav-modules">Modules</a></li>
<li><a href="https://nodejs.org/api/net.html" class="nav-net">Net</a></li>
<li><a href="https://nodejs.org/api/os.html" class="nav-os">OS</a></li>
<li><a href="https://nodejs.org/api/path.html" class="nav-path">Path</a></li>
<li><a href="https://nodejs.org/api/perf_hooks.html" class="nav-perf_hooks">Performance Hooks</a></li>
<li><a href="https://nodejs.org/api/policy.html" class="nav-policy">Policies</a></li>
<li><a href="https://nodejs.org/api/process.html" class="nav-process">Process</a></li>
<li><a href="https://nodejs.org/api/punycode.html" class="nav-punycode">Punycode</a></li>
<li><a href="https://nodejs.org/api/querystring.html" class="nav-querystring">Query Strings</a></li>
<li><a href="https://nodejs.org/api/readline.html" class="nav-readline">Readline</a></li>
<li><a href="https://nodejs.org/api/repl.html" class="nav-repl">REPL</a></li>
<li><a href="https://nodejs.org/api/report.html" class="nav-report">Report</a></li>
<li><a href="https://nodejs.org/api/stream.html" class="nav-stream">Stream</a></li>
<li><a href="https://nodejs.org/api/string_decoder.html" class="nav-string_decoder">String Decoder</a></li>
<li><a href="https://nodejs.org/api/timers.html" class="nav-timers">Timers</a></li>
<li><a href="https://nodejs.org/api/tls.html" class="nav-tls">TLS/SSL</a></li>
<li><a href="https://nodejs.org/api/tracing.html" class="nav-tracing">Trace Events</a></li>
<li><a href="https://nodejs.org/api/tty.html" class="nav-tty">TTY</a></li>
<li><a href="https://nodejs.org/api/dgram.html" class="nav-dgram">UDP/Datagram</a></li>
<li><a href="https://nodejs.org/api/url.html" class="nav-url">URL</a></li>
<li><a href="https://nodejs.org/api/util.html" class="nav-util">Utilities</a></li>
<li><a href="https://nodejs.org/api/v8.html" class="nav-v8">V8</a></li>
<li><a href="https://nodejs.org/api/vm.html" class="nav-vm">VM</a></li>
<li><a href="https://nodejs.org/api/worker_threads.html" class="nav-worker_threads">Worker Threads</a></li>
<li><a href="https://nodejs.org/api/zlib.html" class="nav-zlib">Zlib</a></li>
</ul>
<div class="line"></div>
<ul>
<li><a href="https://github.com/nodejs/node" class="nav-https-github-com-nodejs-node">GitHub Repo & Issue Tracker</a></li>
</ul>
</div>
<div id="column1" data-id="buffer" class="interior">
<header>
<h1>Node.js v12.10.0 Documentation</h1>
<div id="gtoc">
<ul>
<li>
<a href="https://nodejs.org/api/index.html" name="toc">Index</a>
</li>
<li>
<a href="https://nodejs.org/api/all.html">View on single page</a>
</li>
<li>
<a href="https://nodejs.org/api/buffer.json">View as JSON</a>
</li>
<li class="version-picker">
<a href="#">View another version <span>▼</span></a>
<ol class="version-picker"><li><a href="https://nodejs.org/docs/latest-v12.x/api/buffer.html">12.x</a></li>
<li><a href="https://nodejs.org/docs/latest-v11.x/api/buffer.html">11.x</a></li>
<li><a href="https://nodejs.org/docs/latest-v10.x/api/buffer.html">10.x <b>LTS</b></a></li>
<li><a href="https://nodejs.org/docs/latest-v9.x/api/buffer.html">9.x</a></li>
<li><a href="https://nodejs.org/docs/latest-v8.x/api/buffer.html">8.x <b>LTS</b></a></li>
<li><a href="https://nodejs.org/docs/latest-v7.x/api/buffer.html">7.x</a></li>
<li><a href="https://nodejs.org/docs/latest-v6.x/api/buffer.html">6.x</a></li>
<li><a href="https://nodejs.org/docs/latest-v5.x/api/buffer.html">5.x</a></li>
<li><a href="https://nodejs.org/docs/latest-v4.x/api/buffer.html">4.x</a></li>
<li><a href="https://nodejs.org/docs/latest-v0.12.x/api/buffer.html">0.12.x</a></li>
<li><a href="https://nodejs.org/docs/latest-v0.10.x/api/buffer.html">0.10.x</a></li></ol>
</li>
<li class="edit_on_github"><a href="https://github.com/nodejs/node/edit/master/doc/api/buffer.md"><span class="github_icon"><svg height="16" width="16" viewBox="0 0 16.1 16.1" fill="currentColor"><path d="M8 0a8 8 0 0 0-2.5 15.6c.4 0 .5-.2.5-.4v-1.5c-2 .4-2.5-.5-2.7-1 0-.1-.5-.9-.8-1-.3-.2-.7-.6 0-.6.6 0 1 .6 1.2.8.7 1.2 1.9 1 2.4.7 0-.5.2-.9.5-1-1.8-.3-3.7-1-3.7-4 0-.9.3-1.6.8-2.2 0-.2-.3-1 .1-2 0 0 .7-.3 2.2.7a7.4 7.4 0 0 1 4 0c1.5-1 2.2-.8 2.2-.8.5 1.1.2 2 .1 2.1.5.6.8 1.3.8 2.2 0 3-1.9 3.7-3.6 4 .3.2.5.7.5 1.4v2.2c0 .2.1.5.5.4A8 8 0 0 0 16 8a8 8 0 0 0-8-8z"></path></svg></span>Edit on GitHub</a></li>
</ul>
</div>
<hr>
</header>
<div id="toc">
<h2>Table of Contents</h2>
<ul>
<li>
<p><span class="stability_2"><a href="#buffer_buffer">Buffer</a></span></p>
<ul>
<li>
<p><a href="#buffer_buffer_from_buffer_alloc_and_buffer_allocunsafe"><code>Buffer.from()</code>, <code>Buffer.alloc()</code>, and <code>Buffer.allocUnsafe()</code></a></p>
<ul>
<li><a href="#buffer_the_zero_fill_buffers_command_line_option">The <code>--zero-fill-buffers</code> command line option</a></li>
<li><a href="#buffer_what_makes_buffer_allocunsafe_and_buffer_allocunsafeslow_unsafe">What makes <code>Buffer.allocUnsafe()</code> and <code>Buffer.allocUnsafeSlow()</code> "unsafe"?</a></li>
</ul>
</li>
<li><a href="#buffer_buffers_and_character_encodings">Buffers and Character Encodings</a></li>
<li><a href="#buffer_buffers_and_typedarray">Buffers and TypedArray</a></li>
<li><a href="#buffer_buffers_and_iteration">Buffers and iteration</a></li>
<li>
<p><a href="#buffer_class_buffer">Class: Buffer</a></p>
<ul>
<li><span class="stability_0"><a href="#buffer_new_buffer_array">new Buffer(array)</a></span></li>
<li><span class="stability_0"><a href="#buffer_new_buffer_arraybuffer_byteoffset_length">new Buffer(arrayBuffer[, byteOffset[, length]])</a></span></li>
<li><span class="stability_0"><a href="#buffer_new_buffer_buffer">new Buffer(buffer)</a></span></li>
<li><span class="stability_0"><a href="#buffer_new_buffer_size">new Buffer(size)</a></span></li>
<li><span class="stability_0"><a href="#buffer_new_buffer_string_encoding">new Buffer(string[, encoding])</a></span></li>
<li><a href="#buffer_class_method_buffer_alloc_size_fill_encoding">Class Method: Buffer.alloc(size[, fill[, encoding]])</a></li>
<li><a href="#buffer_class_method_buffer_allocunsafe_size">Class Method: Buffer.allocUnsafe(size)</a></li>
<li><a href="#buffer_class_method_buffer_allocunsafeslow_size">Class Method: Buffer.allocUnsafeSlow(size)</a></li>
<li><a href="#buffer_class_method_buffer_bytelength_string_encoding">Class Method: Buffer.byteLength(string[, encoding])</a></li>
<li><a href="#buffer_class_method_buffer_compare_buf1_buf2">Class Method: Buffer.compare(buf1, buf2)</a></li>
<li><a href="#buffer_class_method_buffer_concat_list_totallength">Class Method: Buffer.concat(list[, totalLength])</a></li>
<li><a href="#buffer_class_method_buffer_from_array">Class Method: Buffer.from(array)</a></li>
<li><a href="#buffer_class_method_buffer_from_arraybuffer_byteoffset_length">Class Method: Buffer.from(arrayBuffer[, byteOffset[, length]])</a></li>
<li><a href="#buffer_class_method_buffer_from_buffer">Class Method: Buffer.from(buffer)</a></li>
<li><a href="#buffer_class_method_buffer_from_object_offsetorencoding_length">Class Method: Buffer.from(object[, offsetOrEncoding[, length]])</a></li>
<li><a href="#buffer_class_method_buffer_from_string_encoding">Class Method: Buffer.from(string[, encoding])</a></li>
<li><a href="#buffer_class_method_buffer_isbuffer_obj">Class Method: Buffer.isBuffer(obj)</a></li>
<li><a href="#buffer_class_method_buffer_isencoding_encoding">Class Method: Buffer.isEncoding(encoding)</a></li>
<li><a href="#buffer_class_property_buffer_poolsize">Class Property: Buffer.poolSize</a></li>
<li><a href="#buffer_buf_index">buf[index]</a></li>
<li><a href="#buffer_buf_buffer">buf.buffer</a></li>
<li><a href="#buffer_buf_byteoffset">buf.byteOffset</a></li>
<li><a href="#buffer_buf_compare_target_targetstart_targetend_sourcestart_sourceend">buf.compare(target[, targetStart[, targetEnd[, sourceStart[, sourceEnd]]]])</a></li>
<li><a href="#buffer_buf_copy_target_targetstart_sourcestart_sourceend">buf.copy(target[, targetStart[, sourceStart[, sourceEnd]]])</a></li>
<li><a href="#buffer_buf_entries">buf.entries()</a></li>
<li><a href="#buffer_buf_equals_otherbuffer">buf.equals(otherBuffer)</a></li>
<li><a href="#buffer_buf_fill_value_offset_end_encoding">buf.fill(value[, offset[, end]][, encoding])</a></li>
<li><a href="#buffer_buf_includes_value_byteoffset_encoding">buf.includes(value[, byteOffset][, encoding])</a></li>
<li><a href="#buffer_buf_indexof_value_byteoffset_encoding">buf.indexOf(value[, byteOffset][, encoding])</a></li>
<li><a href="#buffer_buf_keys">buf.keys()</a></li>
<li><a href="#buffer_buf_lastindexof_value_byteoffset_encoding">buf.lastIndexOf(value[, byteOffset][, encoding])</a></li>
<li><a href="#buffer_buf_length">buf.length</a></li>
<li><span class="stability_0"><a href="#buffer_buf_parent">buf.parent</a></span></li>
<li><a href="#buffer_buf_readbigint64be_offset">buf.readBigInt64BE([offset])</a></li>
<li><a href="#buffer_buf_readbigint64le_offset">buf.readBigInt64LE([offset])</a></li>
<li><a href="#buffer_buf_readbiguint64be_offset">buf.readBigUInt64BE([offset])</a></li>
<li><a href="#buffer_buf_readbiguint64le_offset">buf.readBigUInt64LE([offset])</a></li>
<li><a href="#buffer_buf_readdoublebe_offset">buf.readDoubleBE([offset])</a></li>
<li><a href="#buffer_buf_readdoublele_offset">buf.readDoubleLE([offset])</a></li>
<li><a href="#buffer_buf_readfloatbe_offset">buf.readFloatBE([offset])</a></li>
<li><a href="#buffer_buf_readfloatle_offset">buf.readFloatLE([offset])</a></li>
<li><a href="#buffer_buf_readint8_offset">buf.readInt8([offset])</a></li>
<li><a href="#buffer_buf_readint16be_offset">buf.readInt16BE([offset])</a></li>
<li><a href="#buffer_buf_readint16le_offset">buf.readInt16LE([offset])</a></li>
<li><a href="#buffer_buf_readint32be_offset">buf.readInt32BE([offset])</a></li>
<li><a href="#buffer_buf_readint32le_offset">buf.readInt32LE([offset])</a></li>
<li><a href="#buffer_buf_readintbe_offset_bytelength">buf.readIntBE(offset, byteLength)</a></li>
<li><a href="#buffer_buf_readintle_offset_bytelength">buf.readIntLE(offset, byteLength)</a></li>
<li><a href="#buffer_buf_readuint8_offset">buf.readUInt8([offset])</a></li>
<li><a href="#buffer_buf_readuint16be_offset">buf.readUInt16BE([offset])</a></li>
<li><a href="#buffer_buf_readuint16le_offset">buf.readUInt16LE([offset])</a></li>
<li><a href="#buffer_buf_readuint32be_offset">buf.readUInt32BE([offset])</a></li>
<li><a href="#buffer_buf_readuint32le_offset">buf.readUInt32LE([offset])</a></li>
<li><a href="#buffer_buf_readuintbe_offset_bytelength">buf.readUIntBE(offset, byteLength)</a></li>
<li><a href="#buffer_buf_readuintle_offset_bytelength">buf.readUIntLE(offset, byteLength)</a></li>
<li><a href="#buffer_buf_subarray_start_end">buf.subarray([start[, end]])</a></li>
<li><a href="#buffer_buf_slice_start_end">buf.slice([start[, end]])</a></li>
<li><a href="#buffer_buf_swap16">buf.swap16()</a></li>
<li><a href="#buffer_buf_swap32">buf.swap32()</a></li>
<li><a href="#buffer_buf_swap64">buf.swap64()</a></li>
<li><a href="#buffer_buf_tojson">buf.toJSON()</a></li>
<li><a href="#buffer_buf_tostring_encoding_start_end">buf.toString([encoding[, start[, end]]])</a></li>
<li><a href="#buffer_buf_values">buf.values()</a></li>
<li><a href="#buffer_buf_write_string_offset_length_encoding">buf.write(string[, offset[, length]][, encoding])</a></li>
<li><a href="#buffer_buf_writebigint64be_value_offset">buf.writeBigInt64BE(value[, offset])</a></li>
<li><a href="#buffer_buf_writebigint64le_value_offset">buf.writeBigInt64LE(value[, offset])</a></li>
<li><a href="#buffer_buf_writebiguint64be_value_offset">buf.writeBigUInt64BE(value[, offset])</a></li>
<li><a href="#buffer_buf_writebiguint64le_value_offset">buf.writeBigUInt64LE(value[, offset])</a></li>
<li><a href="#buffer_buf_writedoublebe_value_offset">buf.writeDoubleBE(value[, offset])</a></li>
<li><a href="#buffer_buf_writedoublele_value_offset">buf.writeDoubleLE(value[, offset])</a></li>
<li><a href="#buffer_buf_writefloatbe_value_offset">buf.writeFloatBE(value[, offset])</a></li>
<li><a href="#buffer_buf_writefloatle_value_offset">buf.writeFloatLE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeint8_value_offset">buf.writeInt8(value[, offset])</a></li>
<li><a href="#buffer_buf_writeint16be_value_offset">buf.writeInt16BE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeint16le_value_offset">buf.writeInt16LE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeint32be_value_offset">buf.writeInt32BE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeint32le_value_offset">buf.writeInt32LE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeintbe_value_offset_bytelength">buf.writeIntBE(value, offset, byteLength)</a></li>
<li><a href="#buffer_buf_writeintle_value_offset_bytelength">buf.writeIntLE(value, offset, byteLength)</a></li>
<li><a href="#buffer_buf_writeuint8_value_offset">buf.writeUInt8(value[, offset])</a></li>
<li><a href="#buffer_buf_writeuint16be_value_offset">buf.writeUInt16BE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeuint16le_value_offset">buf.writeUInt16LE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeuint32be_value_offset">buf.writeUInt32BE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeuint32le_value_offset">buf.writeUInt32LE(value[, offset])</a></li>
<li><a href="#buffer_buf_writeuintbe_value_offset_bytelength">buf.writeUIntBE(value, offset, byteLength)</a></li>
<li><a href="#buffer_buf_writeuintle_value_offset_bytelength">buf.writeUIntLE(value, offset, byteLength)</a></li>
</ul>
</li>
<li><a href="#buffer_buffer_inspect_max_bytes">buffer.INSPECT_MAX_BYTES</a></li>
<li><a href="#buffer_buffer_kmaxlength">buffer.kMaxLength</a></li>
<li><a href="#buffer_buffer_transcode_source_fromenc_toenc">buffer.transcode(source, fromEnc, toEnc)</a></li>
<li>
<p><span class="stability_0"><a href="#buffer_class_slowbuffer">Class: SlowBuffer</a></span></p>
<ul>
<li><span class="stability_0"><a href="#buffer_new_slowbuffer_size">new SlowBuffer(size)</a></span></li>
</ul>
</li>
<li>
<p><a href="#buffer_buffer_constants">Buffer Constants</a></p>
<ul>
<li><a href="#buffer_buffer_constants_max_length">buffer.constants.MAX_LENGTH</a></li>
<li><a href="#buffer_buffer_constants_max_string_length">buffer.constants.MAX_STRING_LENGTH</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
<div id="apicontent">
<h1>Buffer<span><a class="mark" href="#buffer_buffer" id="buffer_buffer">#</a></span></h1>
<p></p><div class="api_stability api_stability_2"><a href="https://nodejs.org/api/documentation.html#documentation_stability_index">Stability: 2</a> - Stable</div><p></p>
<p>Prior to the introduction of <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>, the JavaScript language had no
mechanism for reading or manipulating streams of binary data. The <code>Buffer</code> class
was introduced as part of the Node.js API to enable interaction with octet
streams in TCP streams, file system operations, and other contexts.</p>
<p>With <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a> now available, the <code>Buffer</code> class implements the
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array"><code>Uint8Array</code></a> API in a manner that is more optimized and suitable for
Node.js.</p>
<p>Instances of the <code>Buffer</code> class are similar to arrays of integers from <code>0</code> to
<code>255</code> (other integers are coerced to this range by <code>& 255</code> operation) but
correspond to fixed-sized, raw memory allocations outside the V8 heap.
The size of the <code>Buffer</code> is established when it is created and cannot be
changed.</p>
<p>The <code>Buffer</code> class is within the global scope, making it unlikely that one
would need to ever use <code>require('buffer').Buffer</code>.</p>
<pre><code class="language-js">// Creates a zero-filled Buffer of length 10.
const buf1 = Buffer.alloc(10);
// Creates a Buffer of length 10, filled with 0x1.
const buf2 = Buffer.alloc(10, 1);
// Creates an uninitialized buffer of length 10.
// This is faster than calling Buffer.alloc() but the returned
// Buffer instance might contain old data that needs to be
// overwritten using either fill() or write().
const buf3 = Buffer.allocUnsafe(10);
// Creates a Buffer containing [0x1, 0x2, 0x3].
const buf4 = Buffer.from([1, 2, 3]);
// Creates a Buffer containing UTF-8 bytes [0x74, 0xc3, 0xa9, 0x73, 0x74].
const buf5 = Buffer.from('tést');
// Creates a Buffer containing Latin-1 bytes [0x74, 0xe9, 0x73, 0x74].
const buf6 = Buffer.from('tést', 'latin1');
</code></pre>
<h2><code>Buffer.from()</code>, <code>Buffer.alloc()</code>, and <code>Buffer.allocUnsafe()</code><span><a class="mark" href="#buffer_buffer_from_buffer_alloc_and_buffer_allocunsafe" id="buffer_buffer_from_buffer_alloc_and_buffer_allocunsafe">#</a></span></h2>
<p>In versions of Node.js prior to 6.0.0, <code>Buffer</code> instances were created using the
<code>Buffer</code> constructor function, which allocates the returned <code>Buffer</code>
differently based on what arguments are provided:</p>
<ul>
<li>Passing a number as the first argument to <code>Buffer()</code> (e.g. <code>new Buffer(10)</code>)
allocates a new <code>Buffer</code> object of the specified size. Prior to Node.js 8.0.0,
the memory allocated for such <code>Buffer</code> instances is <em>not</em> initialized and
<em>can contain sensitive data</em>. Such <code>Buffer</code> instances <em>must</em> be subsequently
initialized by using either <a href="#buffer_buf_fill_value_offset_end_encoding"><code>buf.fill(0)</code></a> or by writing to the
entire <code>Buffer</code>. While this behavior is <em>intentional</em> to improve performance,
development experience has demonstrated that a more explicit distinction is
required between creating a fast-but-uninitialized <code>Buffer</code> versus creating a
slower-but-safer <code>Buffer</code>. Since Node.js 8.0.0, <code>Buffer(num)</code> and <code>new Buffer(num)</code> return a <code>Buffer</code> with initialized memory.</li>
<li>Passing a string, array, or <code>Buffer</code> as the first argument copies the
passed object's data into the <code>Buffer</code>.</li>
<li>Passing an <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer"><code>ArrayBuffer</code></a> or a <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer"><code>SharedArrayBuffer</code></a> returns a <code>Buffer</code>
that shares allocated memory with the given array buffer.</li>
</ul>
<p>Because the behavior of <code>new Buffer()</code> is different depending on the type of the
first argument, security and reliability issues can be inadvertently introduced
into applications when argument validation or <code>Buffer</code> initialization is not
performed.</p>
<p>For example, if an attacker can cause an application to receive a number where
a string is expected, the application may call <code>new Buffer(100)</code>
instead of <code>new Buffer("100")</code>, it will allocate a 100 byte buffer instead
of allocating a 3 byte buffer with content <code>"100"</code>. This is commonly possible
using JSON API calls. Since JSON distinguishes between numeric and string types,
it allows injection of numbers where a naive application might expect to always
receive a string. Before Node.js 8.0.0, the 100 byte buffer might contain
arbitrary pre-existing in-memory data, so may be used to expose in-memory
secrets to a remote attacker. Since Node.js 8.0.0, exposure of memory cannot
occur because the data is zero-filled. However, other attacks are still
possible, such as causing very large buffers to be allocated by the server,
leading to performance degradation or crashing on memory exhaustion.</p>
<p>To make the creation of <code>Buffer</code> instances more reliable and less error-prone,
the various forms of the <code>new Buffer()</code> constructor have been <strong>deprecated</strong>
and replaced by separate <code>Buffer.from()</code>, <a href="#buffer_class_method_buffer_alloc_size_fill_encoding"><code>Buffer.alloc()</code></a>, and
<a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a> methods.</p>
<p><em>Developers should migrate all existing uses of the <code>new Buffer()</code> constructors
to one of these new APIs.</em></p>
<ul>
<li><a href="#buffer_class_method_buffer_from_array"><code>Buffer.from(array)</code></a> returns a new <code>Buffer</code> that <em>contains a copy</em> of the
provided octets.</li>
<li><a href="#buffer_class_method_buffer_from_arraybuffer_byteoffset_length"><code>Buffer.from(arrayBuffer[, byteOffset[, length]])</code></a>
returns a new <code>Buffer</code> that <em>shares the same allocated memory</em> as the given
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer"><code>ArrayBuffer</code></a>.</li>
<li><a href="#buffer_class_method_buffer_from_buffer"><code>Buffer.from(buffer)</code></a> returns a new <code>Buffer</code> that <em>contains a copy</em> of the
contents of the given <code>Buffer</code>.</li>
<li><a href="#buffer_class_method_buffer_from_string_encoding"><code>Buffer.from(string[, encoding])</code></a> returns a new
<code>Buffer</code> that <em>contains a copy</em> of the provided string.</li>
<li><a href="#buffer_class_method_buffer_alloc_size_fill_encoding"><code>Buffer.alloc(size[, fill[, encoding]])</code></a> returns a new
initialized <code>Buffer</code> of the specified size. This method is slower than
<a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe(size)</code></a> but guarantees that newly
created <code>Buffer</code> instances never contain old data that is potentially
sensitive. A <code>TypeError</code> will be thrown if <code>size</code> is not a number.</li>
<li><a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe(size)</code></a> and
<a href="#buffer_class_method_buffer_allocunsafeslow_size"><code>Buffer.allocUnsafeSlow(size)</code></a> each return a
new uninitialized <code>Buffer</code> of the specified <code>size</code>. Because the <code>Buffer</code> is
uninitialized, the allocated segment of memory might contain old data that is
potentially sensitive.</li>
</ul>
<p><code>Buffer</code> instances returned by <a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a> <em>may</em> be allocated off
a shared internal memory pool if <code>size</code> is less than or equal to half
<a href="#buffer_class_property_buffer_poolsize"><code>Buffer.poolSize</code></a>. Instances returned by <a href="#buffer_class_method_buffer_allocunsafeslow_size"><code>Buffer.allocUnsafeSlow()</code></a>
<em>never</em> use the shared internal memory pool.</p>
<h3>The <code>--zero-fill-buffers</code> command line option<span><a class="mark" href="#buffer_the_zero_fill_buffers_command_line_option" id="buffer_the_zero_fill_buffers_command_line_option">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v5.10.0</span>
</div>
<p>Node.js can be started using the <code>--zero-fill-buffers</code> command line option to
cause all newly allocated <code>Buffer</code> instances to be zero-filled upon creation by
default. Before Node.js 8.0.0, this included buffers allocated by <code>new Buffer(size)</code>. Since Node.js 8.0.0, buffers allocated with <code>new</code> are always
zero-filled, whether this option is used or not.
<a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a>, <a href="#buffer_class_method_buffer_allocunsafeslow_size"><code>Buffer.allocUnsafeSlow()</code></a>, and <code>new SlowBuffer(size)</code>. Use of this flag can have a significant negative impact on
performance. Use of the <code>--zero-fill-buffers</code> option is recommended only when
necessary to enforce that newly allocated <code>Buffer</code> instances cannot contain old
data that is potentially sensitive.</p>
<pre><code class="language-txt">$ node --zero-fill-buffers
> Buffer.allocUnsafe(5);
<Buffer 00 00 00 00 00>
</code></pre>
<h3>What makes <code>Buffer.allocUnsafe()</code> and <code>Buffer.allocUnsafeSlow()</code> "unsafe"?<span><a class="mark" href="#buffer_what_makes_buffer_allocunsafe_and_buffer_allocunsafeslow_unsafe" id="buffer_what_makes_buffer_allocunsafe_and_buffer_allocunsafeslow_unsafe">#</a></span></h3>
<p>When calling <a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a> and <a href="#buffer_class_method_buffer_allocunsafeslow_size"><code>Buffer.allocUnsafeSlow()</code></a>, the
segment of allocated memory is <em>uninitialized</em> (it is not zeroed-out). While
this design makes the allocation of memory quite fast, the allocated segment of
memory might contain old data that is potentially sensitive. Using a <code>Buffer</code>
created by <a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a> without <em>completely</em> overwriting the
memory can allow this old data to be leaked when the <code>Buffer</code> memory is read.</p>
<p>While there are clear performance advantages to using
<a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a>, extra care <em>must</em> be taken in order to avoid
introducing security vulnerabilities into an application.</p>
<h2>Buffers and Character Encodings<span><a class="mark" href="#buffer_buffers_and_character_encodings" id="buffer_buffers_and_character_encodings">#</a></span></h2>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v6.4.0</td>
<td><p>Introduced <code>latin1</code> as an alias for <code>binary</code>.</p></td></tr>
<tr><td>v5.0.0</td>
<td><p>Removed the deprecated <code>raw</code> and <code>raws</code> encodings.</p></td></tr>
</tbody></table>
</details>
</div>
<p>When string data is stored in or extracted out of a <code>Buffer</code> instance, a
character encoding may be specified.</p>
<pre><code class="language-js">const buf = Buffer.from('hello world', 'ascii');
console.log(buf.toString('hex'));
// Prints: 68656c6c6f20776f726c64
console.log(buf.toString('base64'));
// Prints: aGVsbG8gd29ybGQ=
console.log(Buffer.from('fhqwhgads', 'ascii'));
// Prints: <Buffer 66 68 71 77 68 67 61 64 73>
console.log(Buffer.from('fhqwhgads', 'utf16le'));
// Prints: <Buffer 66 00 68 00 71 00 77 00 68 00 67 00 61 00 64 00 73 00>
</code></pre>
<p>The character encodings currently supported by Node.js include:</p>
<ul>
<li>
<p><code>'ascii'</code> - For 7-bit ASCII data only. This encoding is fast and will strip
the high bit if set.</p>
</li>
<li>
<p><code>'utf8'</code> - Multibyte encoded Unicode characters. Many web pages and other
document formats use UTF-8.</p>
</li>
<li>
<p><code>'utf16le'</code> - 2 or 4 bytes, little-endian encoded Unicode characters.
Surrogate pairs (U+10000 to U+10FFFF) are supported.</p>
</li>
<li>
<p><code>'ucs2'</code> - Alias of <code>'utf16le'</code>.</p>
</li>
<li>
<p><code>'base64'</code> - Base64 encoding. When creating a <code>Buffer</code> from a string,
this encoding will also correctly accept "URL and Filename Safe Alphabet" as
specified in <a href="https://tools.ietf.org/html/rfc4648#section-5">RFC 4648, Section 5</a>.</p>
</li>
<li>
<p><code>'latin1'</code> - A way of encoding the <code>Buffer</code> into a one-byte encoded string
(as defined by the IANA in <a href="https://tools.ietf.org/html/rfc1345">RFC 1345</a>,
page 63, to be the Latin-1 supplement block and C0/C1 control codes).</p>
</li>
<li>
<p><code>'binary'</code> - Alias for <code>'latin1'</code>.</p>
</li>
<li>
<p><code>'hex'</code> - Encode each byte as two hexadecimal characters.</p>
</li>
</ul>
<p>Modern Web browsers follow the <a href="https://encoding.spec.whatwg.org/">WHATWG Encoding Standard</a> which aliases
both <code>'latin1'</code> and <code>'ISO-8859-1'</code> to <code>'win-1252'</code>. This means that while doing
something like <code>http.get()</code>, if the returned charset is one of those listed in
the WHATWG specification it is possible that the server actually returned
<code>'win-1252'</code>-encoded data, and using <code>'latin1'</code> encoding may incorrectly decode
the characters.</p>
<h2>Buffers and TypedArray<span><a class="mark" href="#buffer_buffers_and_typedarray" id="buffer_buffers_and_typedarray">#</a></span></h2>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v3.0.0</td>
<td><p>The <code>Buffer</code>s class now inherits from <code>Uint8Array</code>.</p></td></tr>
</tbody></table>
</details>
</div>
<p><code>Buffer</code> instances are also <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array"><code>Uint8Array</code></a> instances. However, there are
subtle incompatibilities with <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>. For example, while
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/slice"><code>ArrayBuffer#slice()</code></a> creates a copy of the slice, the implementation of
<a href="#buffer_buf_slice_start_end"><code>Buffer#slice()</code></a> creates a view over the existing <code>Buffer</code>
without copying, making <a href="#buffer_buf_slice_start_end"><code>Buffer#slice()</code></a> far more efficient.</p>
<p>It is also possible to create new <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a> instances from a <code>Buffer</code>
with the following caveats:</p>
<ol>
<li>
<p>The <code>Buffer</code> object's memory is copied to the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>, not shared.</p>
</li>
<li>
<p>The <code>Buffer</code> object's memory is interpreted as an array of distinct
elements, and not as a byte array of the target type. That is,
<code>new Uint32Array(Buffer.from([1, 2, 3, 4]))</code> creates a 4-element
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array"><code>Uint32Array</code></a> with elements <code>[1, 2, 3, 4]</code>, not a <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array"><code>Uint32Array</code></a> with a
single element <code>[0x1020304]</code> or <code>[0x4030201]</code>.</p>
</li>
</ol>
<p>It is possible to create a new <code>Buffer</code> that shares the same allocated memory as
a <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a> instance by using the <code>TypedArray</code> object's <code>.buffer</code>
property.</p>
<pre><code class="language-js">const arr = new Uint16Array(2);
arr[0] = 5000;
arr[1] = 4000;
// Copies the contents of `arr`.
const buf1 = Buffer.from(arr);
// Shares memory with `arr`.
const buf2 = Buffer.from(arr.buffer);
console.log(buf1);
// Prints: <Buffer 88 a0>
console.log(buf2);
// Prints: <Buffer 88 13 a0 0f>
arr[1] = 6000;
console.log(buf1);
// Prints: <Buffer 88 a0>
console.log(buf2);
// Prints: <Buffer 88 13 70 17>
</code></pre>
<p>When creating a <code>Buffer</code> using a <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>'s <code>.buffer</code>, it is
possible to use only a portion of the underlying <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer"><code>ArrayBuffer</code></a> by passing in
<code>byteOffset</code> and <code>length</code> parameters.</p>
<pre><code class="language-js">const arr = new Uint16Array(20);
const buf = Buffer.from(arr.buffer, 0, 16);
console.log(buf.length);
// Prints: 16
</code></pre>
<p>The <code>Buffer.from()</code> and <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/from"><code>TypedArray.from()</code></a> have different signatures and
implementations. Specifically, the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a> variants accept a second
argument that is a mapping function that is invoked on every element of the
typed array:</p>
<ul>
<li><code>TypedArray.from(source[, mapFn[, thisArg]])</code></li>
</ul>
<p>The <code>Buffer.from()</code> method, however, does not support the use of a mapping
function:</p>
<ul>
<li><a href="#buffer_class_method_buffer_from_array"><code>Buffer.from(array)</code></a></li>
<li><a href="#buffer_class_method_buffer_from_buffer"><code>Buffer.from(buffer)</code></a></li>
<li><a href="#buffer_class_method_buffer_from_arraybuffer_byteoffset_length"><code>Buffer.from(arrayBuffer[, byteOffset[, length]])</code></a></li>
<li><a href="#buffer_class_method_buffer_from_string_encoding"><code>Buffer.from(string[, encoding])</code></a></li>
</ul>
<h2>Buffers and iteration<span><a class="mark" href="#buffer_buffers_and_iteration" id="buffer_buffers_and_iteration">#</a></span></h2>
<p><code>Buffer</code> instances can be iterated over using <code>for..of</code> syntax:</p>
<pre><code class="language-js">const buf = Buffer.from([1, 2, 3]);
for (const b of buf) {
console.log(b);
}
// Prints:
// 1
// 2
// 3
</code></pre>
<p>Additionally, the <a href="#buffer_buf_values"><code>buf.values()</code></a>, <a href="#buffer_buf_keys"><code>buf.keys()</code></a>, and
<a href="#buffer_buf_entries"><code>buf.entries()</code></a> methods can be used to create iterators.</p>
<h2>Class: Buffer<span><a class="mark" href="#buffer_class_buffer" id="buffer_class_buffer">#</a></span></h2>
<p>The <code>Buffer</code> class is a global type for dealing with binary data directly.
It can be constructed in a variety of ways.</p>
<h3>new Buffer(array)<span><a class="mark" href="#buffer_new_buffer_array" id="buffer_new_buffer_array">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.0.0</td>
<td><p>Calling this constructor emits a deprecation warning when run from code outside the <code>node_modules</code> directory.</p></td></tr>
<tr><td>v7.2.1</td>
<td><p>Calling this constructor no longer emits a deprecation warning.</p></td></tr>
<tr><td>v7.0.0</td>
<td><p>Calling this constructor emits a deprecation warning now.</p></td></tr>
<tr><td>v6.0.0</td>
<td><p><span>Deprecated since: v6.0.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p></p><div class="api_stability api_stability_0"><a href="https://nodejs.org/api/documentation.html#documentation_stability_index">Stability: 0</a> - Deprecated: Use <a href="#buffer_class_method_buffer_from_array"><code>Buffer.from(array)</code></a> instead.</div><p></p>
<ul>
<li><code>array</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer[]></a> An array of bytes to copy from.</li>
</ul>
<p>Allocates a new <code>Buffer</code> using an <code>array</code> of octets.</p>
<pre><code class="language-js">// Creates a new Buffer containing the UTF-8 bytes of the string 'buffer'.
const buf = new Buffer([0x62, 0x75, 0x66, 0x66, 0x65, 0x72]);
</code></pre>
<h3>new Buffer(arrayBuffer[, byteOffset[, length]])<span><a class="mark" href="#buffer_new_buffer_arraybuffer_byteoffset_length" id="buffer_new_buffer_arraybuffer_byteoffset_length">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.0.0</td>
<td><p>Calling this constructor emits a deprecation warning when run from code outside the <code>node_modules</code> directory.</p></td></tr>
<tr><td>v7.2.1</td>
<td><p>Calling this constructor no longer emits a deprecation warning.</p></td></tr>
<tr><td>v7.0.0</td>
<td><p>Calling this constructor emits a deprecation warning now.</p></td></tr>
<tr><td>v6.0.0</td>
<td><p>The <code>byteOffset</code> and <code>length</code> parameters are supported now.</p></td></tr>
<tr><td>v6.0.0</td>
<td><p><span>Deprecated since: v6.0.0</span></p></td></tr>
<tr><td>v3.0.0</td>
<td><p><span>Added in: v3.0.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p></p><div class="api_stability api_stability_0"><a href="https://nodejs.org/api/documentation.html#documentation_stability_index">Stability: 0</a> - Deprecated: Use
<a href="#buffer_class_method_buffer_from_arraybuffer_byteoffset_length"><code>Buffer.from(arrayBuffer[, byteOffset[, length]])</code></a>
instead.</div><p></p>
<ul>
<li><code>arrayBuffer</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer" class="type"><ArrayBuffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer" class="type"><SharedArrayBuffer></a> An <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer"><code>ArrayBuffer</code></a>,
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer"><code>SharedArrayBuffer</code></a> or the <code>.buffer</code> property of a <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>.</li>
<li><code>byteOffset</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Index of first byte to expose. <strong>Default:</strong> <code>0</code>.</li>
<li><code>length</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Number of bytes to expose.
<strong>Default:</strong> <code>arrayBuffer.length - byteOffset</code>.</li>
</ul>
<p>This creates a view of the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer"><code>ArrayBuffer</code></a> or <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer"><code>SharedArrayBuffer</code></a> without
copying the underlying memory. For example, when passed a reference to the
<code>.buffer</code> property of a <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a> instance, the newly created <code>Buffer</code>
will share the same allocated memory as the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>.</p>
<p>The optional <code>byteOffset</code> and <code>length</code> arguments specify a memory range within
the <code>arrayBuffer</code> that will be shared by the <code>Buffer</code>.</p>
<pre><code class="language-js">const arr = new Uint16Array(2);
arr[0] = 5000;
arr[1] = 4000;
// Shares memory with `arr`.
const buf = new Buffer(arr.buffer);
console.log(buf);
// Prints: <Buffer 88 13 a0 0f>
// Changing the original Uint16Array changes the Buffer also.
arr[1] = 6000;
console.log(buf);
// Prints: <Buffer 88 13 70 17>
</code></pre>
<h3>new Buffer(buffer)<span><a class="mark" href="#buffer_new_buffer_buffer" id="buffer_new_buffer_buffer">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.0.0</td>
<td><p>Calling this constructor emits a deprecation warning when run from code outside the <code>node_modules</code> directory.</p></td></tr>
<tr><td>v7.2.1</td>
<td><p>Calling this constructor no longer emits a deprecation warning.</p></td></tr>
<tr><td>v7.0.0</td>
<td><p>Calling this constructor emits a deprecation warning now.</p></td></tr>
<tr><td>v6.0.0</td>
<td><p><span>Deprecated since: v6.0.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p></p><div class="api_stability api_stability_0"><a href="https://nodejs.org/api/documentation.html#documentation_stability_index">Stability: 0</a> - Deprecated: Use <a href="#buffer_class_method_buffer_from_buffer"><code>Buffer.from(buffer)</code></a> instead.</div><p></p>
<ul>
<li><code>buffer</code> <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array" class="type"><Uint8Array></a> An existing <code>Buffer</code> or <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array"><code>Uint8Array</code></a> from
which to copy data.</li>
</ul>
<p>Copies the passed <code>buffer</code> data onto a new <code>Buffer</code> instance.</p>
<pre><code class="language-js">const buf1 = new Buffer('buffer');
const buf2 = new Buffer(buf1);
buf1[0] = 0x61;
console.log(buf1.toString());
// Prints: auffer
console.log(buf2.toString());
// Prints: buffer
</code></pre>
<h3>new Buffer(size)<span><a class="mark" href="#buffer_new_buffer_size" id="buffer_new_buffer_size">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.0.0</td>
<td><p>Calling this constructor emits a deprecation warning when run from code outside the <code>node_modules</code> directory.</p></td></tr>
<tr><td>v8.0.0</td>
<td><p>The <code>new Buffer(size)</code> will return zero-filled memory by default.</p></td></tr>
<tr><td>v7.2.1</td>
<td><p>Calling this constructor no longer emits a deprecation warning.</p></td></tr>
<tr><td>v7.0.0</td>
<td><p>Calling this constructor emits a deprecation warning now.</p></td></tr>
<tr><td>v6.0.0</td>
<td><p><span>Deprecated since: v6.0.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p></p><div class="api_stability api_stability_0"><a href="https://nodejs.org/api/documentation.html#documentation_stability_index">Stability: 0</a> - Deprecated: Use <a href="#buffer_class_method_buffer_alloc_size_fill_encoding"><code>Buffer.alloc()</code></a> instead (also see
<a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a>).</div><p></p>
<ul>
<li><code>size</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> The desired length of the new <code>Buffer</code>.</li>
</ul>
<p>Allocates a new <code>Buffer</code> of <code>size</code> bytes. If <code>size</code> is larger than
<a href="#buffer_buffer_constants_max_length"><code>buffer.constants.MAX_LENGTH</code></a> or smaller than 0, <a href="https://nodejs.org/api/errors.html#ERR_INVALID_OPT_VALUE"><code>ERR_INVALID_OPT_VALUE</code></a>
is thrown. A zero-length <code>Buffer</code> is created if <code>size</code> is 0.</p>
<p>Prior to Node.js 8.0.0, the underlying memory for <code>Buffer</code> instances
created in this way is <em>not initialized</em>. The contents of a newly created
<code>Buffer</code> are unknown and <em>may contain sensitive data</em>. Use
<a href="#buffer_class_method_buffer_alloc_size_fill_encoding"><code>Buffer.alloc(size)</code></a> instead to initialize a <code>Buffer</code>
with zeroes.</p>
<pre><code class="language-js">const buf = new Buffer(10);
console.log(buf);
// Prints: <Buffer 00 00 00 00 00 00 00 00 00 00>
</code></pre>
<h3>new Buffer(string[, encoding])<span><a class="mark" href="#buffer_new_buffer_string_encoding" id="buffer_new_buffer_string_encoding">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.0.0</td>
<td><p>Calling this constructor emits a deprecation warning when run from code outside the <code>node_modules</code> directory.</p></td></tr>
<tr><td>v7.2.1</td>
<td><p>Calling this constructor no longer emits a deprecation warning.</p></td></tr>
<tr><td>v7.0.0</td>
<td><p>Calling this constructor emits a deprecation warning now.</p></td></tr>
<tr><td>v6.0.0</td>
<td><p><span>Deprecated since: v6.0.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p></p><div class="api_stability api_stability_0"><a href="https://nodejs.org/api/documentation.html#documentation_stability_index">Stability: 0</a> - Deprecated:
Use <a href="#buffer_class_method_buffer_from_string_encoding"><code>Buffer.from(string[, encoding])</code></a> instead.</div><p></p>
<ul>
<li><code>string</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> String to encode.</li>
<li><code>encoding</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The encoding of <code>string</code>. <strong>Default:</strong> <code>'utf8'</code>.</li>
</ul>
<p>Creates a new <code>Buffer</code> containing <code>string</code>. The <code>encoding</code> parameter identifies
the character encoding of <code>string</code>.</p>
<pre><code class="language-js">const buf1 = new Buffer('this is a tést');
const buf2 = new Buffer('7468697320697320612074c3a97374', 'hex');
console.log(buf1.toString());
// Prints: this is a tést
console.log(buf2.toString());
// Prints: this is a tést
console.log(buf1.toString('ascii'));
// Prints: this is a tC)st
</code></pre>
<h3>Class Method: Buffer.alloc(size[, fill[, encoding]])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/buffer.js#L332">[src]</a><span><a class="mark" href="#buffer_class_method_buffer_alloc_size_fill_encoding" id="buffer_class_method_buffer_alloc_size_fill_encoding">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.0.0</td>
<td><p>Attempting to fill a non-zero length buffer with a zero length buffer triggers a thrown exception.</p></td></tr>
<tr><td>v10.0.0</td>
<td><p>Specifying an invalid string for <code>fill</code> triggers a thrown exception.</p></td></tr>
<tr><td>v8.9.3</td>
<td><p>Specifying an invalid string for <code>fill</code> now results in a zero-filled buffer.</p></td></tr>
<tr><td>v5.10.0</td>
<td><p><span>Added in: v5.10.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>size</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> The desired length of the new <code>Buffer</code>.</li>
<li><code>fill</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> | <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array" class="type"><Uint8Array></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> A value to pre-fill the new <code>Buffer</code>
with. <strong>Default:</strong> <code>0</code>.</li>
<li><code>encoding</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> If <code>fill</code> is a string, this is its encoding.
<strong>Default:</strong> <code>'utf8'</code>.</li>
</ul>
<p>Allocates a new <code>Buffer</code> of <code>size</code> bytes. If <code>fill</code> is <code>undefined</code>, the
<code>Buffer</code> will be <em>zero-filled</em>.</p>
<pre><code class="language-js">const buf = Buffer.alloc(5);
console.log(buf);
// Prints: <Buffer 00 00 00 00 00>
</code></pre>
<p>If <code>size</code> is larger than
<a href="#buffer_buffer_constants_max_length"><code>buffer.constants.MAX_LENGTH</code></a> or smaller than 0, <a href="https://nodejs.org/api/errors.html#ERR_INVALID_OPT_VALUE"><code>ERR_INVALID_OPT_VALUE</code></a>
is thrown. A zero-length <code>Buffer</code> is created if <code>size</code> is 0.</p>
<p>If <code>fill</code> is specified, the allocated <code>Buffer</code> will be initialized by calling
<a href="#buffer_buf_fill_value_offset_end_encoding"><code>buf.fill(fill)</code></a>.</p>
<pre><code class="language-js">const buf = Buffer.alloc(5, 'a');
console.log(buf);
// Prints: <Buffer 61 61 61 61 61>
</code></pre>
<p>If both <code>fill</code> and <code>encoding</code> are specified, the allocated <code>Buffer</code> will be
initialized by calling <a href="#buffer_buf_fill_value_offset_end_encoding"><code>buf.fill(fill, encoding)</code></a>.</p>
<pre><code class="language-js">const buf = Buffer.alloc(11, 'aGVsbG8gd29ybGQ=', 'base64');
console.log(buf);
// Prints: <Buffer 68 65 6c 6c 6f 20 77 6f 72 6c 64>
</code></pre>
<p>Calling <a href="#buffer_class_method_buffer_alloc_size_fill_encoding"><code>Buffer.alloc()</code></a> can be significantly slower than the alternative
<a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a> but ensures that the newly created <code>Buffer</code> instance
contents will <em>never contain sensitive data</em>.</p>
<p>A <code>TypeError</code> will be thrown if <code>size</code> is not a number.</p>
<h3>Class Method: Buffer.allocUnsafe(size)<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/buffer.js#L345">[src]</a><span><a class="mark" href="#buffer_class_method_buffer_allocunsafe_size" id="buffer_class_method_buffer_allocunsafe_size">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v7.0.0</td>
<td><p>Passing a negative <code>size</code> will now throw an error.</p></td></tr>
<tr><td>v5.10.0</td>
<td><p><span>Added in: v5.10.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>size</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> The desired length of the new <code>Buffer</code>.</li>
</ul>
<p>Allocates a new <code>Buffer</code> of <code>size</code> bytes. If <code>size</code> is larger than
<a href="#buffer_buffer_constants_max_length"><code>buffer.constants.MAX_LENGTH</code></a> or smaller than 0, <a href="https://nodejs.org/api/errors.html#ERR_INVALID_OPT_VALUE"><code>ERR_INVALID_OPT_VALUE</code></a>
is thrown. A zero-length <code>Buffer</code> is created if <code>size</code> is 0.</p>
<p>The underlying memory for <code>Buffer</code> instances created in this way is <em>not
initialized</em>. The contents of the newly created <code>Buffer</code> are unknown and
<em>may contain sensitive data</em>. Use <a href="#buffer_class_method_buffer_alloc_size_fill_encoding"><code>Buffer.alloc()</code></a> instead to initialize
<code>Buffer</code> instances with zeroes.</p>
<pre><code class="language-js">const buf = Buffer.allocUnsafe(10);
console.log(buf);
// Prints (contents may vary): <Buffer a0 8b 28 3f 01 00 00 00 50 32>
buf.fill(0);
console.log(buf);
// Prints: <Buffer 00 00 00 00 00 00 00 00 00 00>
</code></pre>
<p>A <code>TypeError</code> will be thrown if <code>size</code> is not a number.</p>
<p>The <code>Buffer</code> module pre-allocates an internal <code>Buffer</code> instance of
size <a href="#buffer_class_property_buffer_poolsize"><code>Buffer.poolSize</code></a> that is used as a pool for the fast allocation of new
<code>Buffer</code> instances created using <a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a> and the deprecated
<code>new Buffer(size)</code> constructor only when <code>size</code> is less than or equal to
<code>Buffer.poolSize >> 1</code> (floor of <a href="#buffer_class_property_buffer_poolsize"><code>Buffer.poolSize</code></a> divided by two).</p>
<p>Use of this pre-allocated internal memory pool is a key difference between
calling <code>Buffer.alloc(size, fill)</code> vs. <code>Buffer.allocUnsafe(size).fill(fill)</code>.
Specifically, <code>Buffer.alloc(size, fill)</code> will <em>never</em> use the internal <code>Buffer</code>
pool, while <code>Buffer.allocUnsafe(size).fill(fill)</code> <em>will</em> use the internal
<code>Buffer</code> pool if <code>size</code> is less than or equal to half <a href="#buffer_class_property_buffer_poolsize"><code>Buffer.poolSize</code></a>. The
difference is subtle but can be important when an application requires the
additional performance that <a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a> provides.</p>
<h3>Class Method: Buffer.allocUnsafeSlow(size)<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/buffer.js#L355">[src]</a><span><a class="mark" href="#buffer_class_method_buffer_allocunsafeslow_size" id="buffer_class_method_buffer_allocunsafeslow_size">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v5.12.0</span>
</div>
<ul>
<li><code>size</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> The desired length of the new <code>Buffer</code>.</li>
</ul>
<p>Allocates a new <code>Buffer</code> of <code>size</code> bytes. If <code>size</code> is larger than
<a href="#buffer_buffer_constants_max_length"><code>buffer.constants.MAX_LENGTH</code></a> or smaller than 0, <a href="https://nodejs.org/api/errors.html#ERR_INVALID_OPT_VALUE"><code>ERR_INVALID_OPT_VALUE</code></a>
is thrown. A zero-length <code>Buffer</code> is created if <code>size</code> is 0.</p>
<p>The underlying memory for <code>Buffer</code> instances created in this way is <em>not
initialized</em>. The contents of the newly created <code>Buffer</code> are unknown and
<em>may contain sensitive data</em>. Use <a href="#buffer_buf_fill_value_offset_end_encoding"><code>buf.fill(0)</code></a> to initialize
such <code>Buffer</code> instances with zeroes.</p>
<p>When using <a href="#buffer_class_method_buffer_allocunsafe_size"><code>Buffer.allocUnsafe()</code></a> to allocate new <code>Buffer</code> instances,
allocations under 4KB are sliced from a single pre-allocated <code>Buffer</code>. This
allows applications to avoid the garbage collection overhead of creating many
individually allocated <code>Buffer</code> instances. This approach improves both
performance and memory usage by eliminating the need to track and clean up as
many persistent objects.</p>
<p>However, in the case where a developer may need to retain a small chunk of
memory from a pool for an indeterminate amount of time, it may be appropriate
to create an un-pooled <code>Buffer</code> instance using <code>Buffer.allocUnsafeSlow()</code> and
then copying out the relevant bits.</p>
<pre><code class="language-js">// Need to keep around a few small chunks of memory.
const store = [];
socket.on('readable', () => {
let data;
while (null !== (data = readable.read())) {
// Allocate for retained data.
const sb = Buffer.allocUnsafeSlow(10);
// Copy the data into the new allocation.
data.copy(sb, 0, 0, 10);
store.push(sb);
}
});
</code></pre>
<p><code>Buffer.allocUnsafeSlow()</code> should be used only as a last resort after a
developer has observed undue memory retention in their applications.</p>
<p>A <code>TypeError</code> will be thrown if <code>size</code> is not a number.</p>
<h3>Class Method: Buffer.byteLength(string[, encoding])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/buffer.js#L687">[src]</a><span><a class="mark" href="#buffer_class_method_buffer_bytelength_string_encoding" id="buffer_class_method_buffer_bytelength_string_encoding">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v7.0.0</td>
<td><p>Passing invalid input will now throw an error.</p></td></tr>
<tr><td>v5.10.0</td>
<td><p>The <code>string</code> parameter can now be any <code>TypedArray</code>, <code>DataView</code> or <code>ArrayBuffer</code>.</p></td></tr>
<tr><td>v0.1.90</td>
<td><p><span>Added in: v0.1.90</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>string</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> | <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray" class="type"><TypedArray></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView" class="type"><DataView></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer" class="type"><ArrayBuffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer" class="type"><SharedArrayBuffer></a> A
value to calculate the length of.</li>
<li><code>encoding</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> If <code>string</code> is a string, this is its encoding.
<strong>Default:</strong> <code>'utf8'</code>.</li>
<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> The number of bytes contained within <code>string</code>.</li>
</ul>
<p>Returns the actual byte length of a string. This is not the same as
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length"><code>String.prototype.length</code></a> since that returns the number of <em>characters</em> in
a string.</p>
<p>For <code>'base64'</code> and <code>'hex'</code>, this function assumes valid input. For strings that
contain non-Base64/Hex-encoded data (e.g. whitespace), the return value might be
greater than the length of a <code>Buffer</code> created from the string.</p>
<pre><code class="language-js">const str = '\u00bd + \u00bc = \u00be';
console.log(`${str}: ${str.length} characters, ` +
`${Buffer.byteLength(str, 'utf8')} bytes`);
// Prints: ½ + ¼ = ¾: 9 characters, 12 bytes
</code></pre>
<p>When <code>string</code> is a <code>Buffer</code>/<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView"><code>DataView</code></a>/<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>/<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer"><code>ArrayBuffer</code></a>/
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer"><code>SharedArrayBuffer</code></a>, the actual byte length is returned.</p>
<h3>Class Method: Buffer.compare(buf1, buf2)<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/buffer.js#L489">[src]</a><span><a class="mark" href="#buffer_class_method_buffer_compare_buf1_buf2" id="buffer_class_method_buffer_compare_buf1_buf2">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v8.0.0</td>
<td><p>The arguments can now be <code>Uint8Array</code>s.</p></td></tr>
<tr><td>v0.11.13</td>
<td><p><span>Added in: v0.11.13</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>buf1</code> <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array" class="type"><Uint8Array></a></li>
<li><code>buf2</code> <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array" class="type"><Uint8Array></a></li>
<li>Returns: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a></li>
</ul>
<p>Compares <code>buf1</code> to <code>buf2</code> typically for the purpose of sorting arrays of
<code>Buffer</code> instances. This is equivalent to calling
<a href="#buffer_buf_compare_target_targetstart_targetend_sourcestart_sourceend"><code>buf1.compare(buf2)</code></a>.</p>
<pre><code class="language-js">const buf1 = Buffer.from('1234');
const buf2 = Buffer.from('0123');
const arr = [buf1, buf2];
console.log(arr.sort(Buffer.compare));
// Prints: [ <Buffer 30 31 32 33>, <Buffer 31 32 33 34> ]
// (This result is equal to: [buf2, buf1].)
</code></pre>
<h3>Class Method: Buffer.concat(list[, totalLength])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/buffer.js#L511">[src]</a><span><a class="mark" href="#buffer_class_method_buffer_concat_list_totallength" id="buffer_class_method_buffer_concat_list_totallength">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v8.0.0</td>
<td><p>The elements of <code>list</code> can now be <code>Uint8Array</code>s.</p></td></tr>
<tr><td>v0.7.11</td>
<td><p><span>Added in: v0.7.11</span></p></td></tr>
</tbody></table>
</details>
</div>
<ul>
<li><code>list</code> <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer[]></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array" class="type"><Uint8Array[]></a> List of <code>Buffer</code> or <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array"><code>Uint8Array</code></a>
instances to concat.</li>
<li><code>totalLength</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Total length of the <code>Buffer</code> instances in <code>list</code>
when concatenated.</li>
<li>Returns: <a href="https://nodejs.org/api/buffer.html#buffer_class_buffer" class="type"><Buffer></a></li>
</ul>
<p>Returns a new <code>Buffer</code> which is the result of concatenating all the <code>Buffer</code>
instances in the <code>list</code> together.</p>
<p>If the list has no items, or if the <code>totalLength</code> is 0, then a new zero-length
<code>Buffer</code> is returned.</p>
<p>If <code>totalLength</code> is not provided, it is calculated from the <code>Buffer</code> instances
in <code>list</code>. This however causes an additional loop to be executed in order to
calculate the <code>totalLength</code>, so it is faster to provide the length explicitly if
it is already known.</p>
<p>If <code>totalLength</code> is provided, it is coerced to an unsigned integer. If the
combined length of the <code>Buffer</code>s in <code>list</code> exceeds <code>totalLength</code>, the result is
truncated to <code>totalLength</code>.</p>
<pre><code class="language-js">// Create a single `Buffer` from a list of three `Buffer` instances.
const buf1 = Buffer.alloc(10);
const buf2 = Buffer.alloc(14);
const buf3 = Buffer.alloc(18);
const totalLength = buf1.length + buf2.length + buf3.length;
console.log(totalLength);
// Prints: 42
const bufA = Buffer.concat([buf1, buf2, buf3], totalLength);
console.log(bufA);
// Prints: <Buffer 00 00 00 00 ...>
console.log(bufA.length);
// Prints: 42
</code></pre>
<h3>Class Method: Buffer.from(array)<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/buffer.js#L270">[src]</a><span><a class="mark" href="#buffer_class_method_buffer_from_array" id="buffer_class_method_buffer_from_array">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v5.10.0</span>
</div>
<ul>
<li><code>array</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer[]></a></li>
</ul>
<p>Allocates a new <code>Buffer</code> using an <code>array</code> of octets.</p>
<pre><code class="language-js">// Creates a new Buffer containing UTF-8 bytes of the string 'buffer'.
const buf = Buffer.from([0x62, 0x75, 0x66, 0x66, 0x65, 0x72]);
</code></pre>
<p>A <code>TypeError</code> will be thrown if <code>array</code> is not an <code>Array</code> or other type
appropriate for <code>Buffer.from()</code> variants.</p>
<h3>Class Method: Buffer.from(arrayBuffer[, byteOffset[, length]])<a class="srclink" href="https://github.com/nodejs/node/blob/3a2e75d9a5c31d20e429d505b82dd182e33f459a/lib/buffer.js#L270">[src]</a><span><a class="mark" href="#buffer_class_method_buffer_from_arraybuffer_byteoffset_length" id="buffer_class_method_buffer_from_arraybuffer_byteoffset_length">#</a></span></h3>
<div class="api_metadata">
<span>Added in: v5.10.0</span>
</div>
<ul>
<li><code>arrayBuffer</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer" class="type"><ArrayBuffer></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer" class="type"><SharedArrayBuffer></a> An <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer"><code>ArrayBuffer</code></a>,
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer"><code>SharedArrayBuffer</code></a>, or the <code>.buffer</code> property of a <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>.</li>
<li><code>byteOffset</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Index of first byte to expose. <strong>Default:</strong> <code>0</code>.</li>
<li><code>length</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><integer></a> Number of bytes to expose.
<strong>Default:</strong> <code>arrayBuffer.length - byteOffset</code>.</li>
</ul>
<p>This creates a view of the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer"><code>ArrayBuffer</code></a> without copying the underlying
memory. For example, when passed a reference to the <code>.buffer</code> property of a
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a> instance, the newly created <code>Buffer</code> will share the same
allocated memory as the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray"><code>TypedArray</code></a>.</p>
<pre><code class="language-js">const arr = new Uint16Array(2);
arr[0] = 5000;
arr[1] = 4000;
// Shares memory with `arr`.
const buf = Buffer.from(arr.buffer);
console.log(buf);