JavaScript克隆对象的三个实用方法

方法1

function clone(obj){
    var o;
    if(typeof obj == "object"){
        if(obj === null){
            o = null;
        }else{
            if(obj instanceof Array){
                o = [];
                for(var i = 0, len = obj.length; i < len; i++){
                    o.push(clone(obj[i]));
                }
            }else{
                o = {};
                for(var k in obj){
                    o[k] = clone(obj[k]);
                }
            }
        }
    }else{
        o = obj;
    }
    return o;
}

方法2

function clone(obj){
    var o, obj;
    if (obj.constructor == Object){
        o = new obj.constructor(); 
    }else{
        o = new obj.constructor(obj.valueOf()); 
    }
    for(var key in obj){
        if ( o[key] != obj[key] ){ 
            if ( typeof(obj[key]) == 'object' ){ 
                o[key] = clone(obj[key]);
            }else{
                o[key] = obj[key];
            }
        }
    }
    o.toString = obj.toString;
    o.valueOf = obj.valueOf;
    return o;
}

方法3

function clone(obj){
    function Fn(){}
    Fn.prototype = obj;
    var o = new Fn();
    for(var a in o){
        if(typeof o[a] == "object") {
            o[a] = clone(o[a]);
        }
    }
    return o;
}