/* Stack!!

* A stack is exactly what it sounds like. An element gets added to the top of

* the stack and only the element on the top may be removed. This is an example

* of an array implementation of a Stack. So an element can only be added/removed

* from the end of the array.

*/

// Functions: push, pop, peek, view, length

// Creates a stack constructor

const Stack = (function () {

function Stack () {

// The top of the Stack

this.top = 0

// The array representation of the stack

this.stack = []

}

// Adds a value onto the end of the stack

Stack.prototype.push = function (value) {

this.stack[this.top] = value

this.top++

}

// Removes and returns the value at the end of the stack

Stack.prototype.pop = function () {

if (this.top === 0) {

return 'Stack is Empty'

}

this.top--

const result = this.stack[this.top]

this.stack = this.stack.splice(0, this.top)

return result

}

// Returns the size of the stack

Stack.prototype.size = function () {

return this.top

}

// Returns the value at the end of the stack

Stack.prototype.peek = function () {

return this.stack[this.top - 1]

}

// To see all the elements in the stack

Stack.prototype.view = function (output = value => console.log(value)) {

for (let i = 0; i < this.top; i++) {

output(this.stack[i])

}

}

return Stack

}())

export { Stack }