'use strict';
/**
* Create a FILO stack data structure.
* @constructor
*/
function Stack() {
this.stack = [];
}
/**
* Get the number of objects in the stack.
* @returns {number} Number of elements in the stack.
*/
Stack.prototype.size = function() {
return this.stack.length;
};
/**
* Clear the contents of the stack.
*/
Stack.prototype.clear = function() {
this.stack = [];
};
/**
* Push an object in to the stack.
* @param {object} obj - Any object to be pushed into the stack.
*/
Stack.prototype.push = function(obj) {
this.stack.push(obj);
};
/**
* Get the front element of the stack and removes it from the stack.
* @returns {object} Front element from the stack.
*/
Stack.prototype.pop = function() {
var len = this.stack.length;
var obj = this.stack[len-1];
this.stack.splice(len-1,1);
return obj;
};
/**
* Get the front element of the stack without removing it from the stack.
* @returns {object} Front element from the stack.
*/
Stack.prototype.peek = function() {
var len = this.stack.length;
var obj = this.stack[len-1];
return obj;
};
/**
* Checks if the stack isn't empty.
* @returns {boolean} Whether or not the stack has another element. True if yes.
*/
Stack.prototype.hasNext = function() {
return this.stack.length !== 0;
};
/**
* Checks if the stack is empty.
* @returns {boolean} Whether or not the stack is empty. True if yes.
*/
Stack.prototype.isEmpty = function() {
return this.stack.length === 0;
};
module.exports = Stack;