栈和队列

栈（先进后出）

function Stack () {
    this.arr = [];
    this.push = function (value) {
        this.arr.push(value);
    }
    this.pop = function () {
        return this.arr.pop();
    }
}

var stack = new Stack();
stack.push(1);
stack.push(2);
stack.push(3);
console.log(stack.arr);  //--> [1, 2, 3]
stack.pop();
console.log(stack.arr);  //--> [1, 2]

队列（先进先出）

function Queue () {
    this.arr = [];
    this.push = function (value) {
        this.arr.push(value);
    }
    this.shift = function () {
        return this.arr.shift();
    }
}

var queue = new Queue();
queue.push(1);
queue.push(2);
queue.push(3);
console.log(queue.arr);
queue.shift();
console.log(queue.arr);