使用 JavaScript 实现栈

1.栈的基本操作

    function Stack() {
        //使用数组保存栈元素
        var items = [];

        //添加新元素到栈顶(相当于数组的末尾)
        this.push = function(element) {
            items.push(element);
        };

        //移除栈顶的元素，同时返回被移除的元素
        this.pop = function() {
            return items.pop();
        };

        //返回栈顶的元素，不对栈做任何修改
        this.peek = function() {
            return items[items.length - 1];
        };

        //如果栈里没有任何元素就返回true，否则返回false
        this.isEmpty = function() {
            return items.length == 0;
        };

        //移除栈里的所有元素
        this.clear = function() {
            items = [];
        };

        //返回栈里的元素个数，和数组的length很像
        this.size = function() {
            return items.length;
        };

        //返回栈里的内容
        this.print = function() {
            //return items.toString();
            return items;
        };
    }

使用该方法：

    var stack = new Stack();
    console.log(stack.isEmpty());    //true

    stack.push(1);
    stack.push(3);
    stack.push(5);
    stack.push(7);
    console.log(stack.peek());       //7
    console.log(stack.print());      //[1, 3, 5, 7]
    console.log(stack.isEmpty());    //false
    console.log(stack.size());       //4

    console.log(stack.pop());        //7
    console.log(stack.peek());       //5
    console.log(stack.print());      // [1, 3, 5]

2.基于该方法实现十进制数转换为二进制数

    //十进制转换为二进制
    function divideBy2(decNumber) {
        var remStack = new Stack(),
            rem,
            binaryString = '';

        while (decNumber > 0) {
            rem = Math.floor(decNumber % 2);
            remStack.push(rem);
            decNumber = Math.floor(decNumber / 2);
        }

        while (!remStack.isEmpty()) {
            binaryString += remStack.pop().toString();
        }

        return binaryString;
    }

    var decNumber = 10;
    console.log(decNumber + '转换为二进制数为：' + divideBy2(decNumber));       //10转换为二进制数为：1010

3.基于该方法实现十进制数转换为二/八/十六进制数

    //十进制转换为任意进制
    function baseConverter(decNumber, base) {
        var remStack = new Stack(),
            rem,
            baseString = '',
            digits = '0123456789ABCDEF';

        while(decNumber > 0) {
            rem = Math.floor(decNumber % base);
            remStack.push(rem);
            decNumber = Math.floor(decNumber / base);
        }

        while(!remStack.isEmpty()) {
            baseString += digits[remStack.pop()];
        }

        return baseString;
    }

    var decNumber = 552;
    var base = 16;
    console.log(decNumber + '转换为' + base + '进制数为：' + baseConverter(decNumber, base));       //552转换为16进制数为：228