[ Javascript ] - 20140724-题目1

[ Javascript ] - 20140724-题目1

// 感谢[广州—坚壳]贡献
实现一个方法，使其达到如下的输出结果，比如：
fn(2); ==> 2;
fn(2)(3); ==> 6;
fn(2)(3)(3); ==> 18;


PS:
1. 回复时注意加上下面这句话，才会有语法高亮或格式缩进。
```javascript
// you code
```
2. 粘贴代码时请使用shift+tab，缩进前面的空白。  

//利用console
var timer = null,
    counter = 1;
var fn = function(a){
    clearTimeout(timer);
    counter = counter*a;
    timer = setTimeout(function(){
        console.log(counter);
        counter = 1;
    },10)
    return arguments.callee;
};
fn(2)(2)(4);
//利用toString
var foo = (function(){
    var counter = 1,
        timer;
    var fn = function(a){
        clearTimeout(timer);
        timer = setTimeout(function(){
            counter = 1
        },10);
        counter*=a;
        return arguments.callee;
    };
    fn.toString = function(){
        return counter;
    };
    return fn;
})();

//方法一，利用function是对象，对象可以设置自定义属性的特点
function fn(n){
    !fn.first && (fn.re = 1,fn.first = true)
    fn.re *= n;
    fn.toString = function(){
        return fn.re;
    };
    return fn;
}
console.log(fn(2)(3))
//方法二：闭包
var fn = (function(){
    var r = 1,
        f = function(n){
            r *= n;
            return f;
        }
    f.toString = function(){
        return r;
    }
    return f;
})();

console.log(fn(2)(3))