js 对象和Json的转换，js及深度复制

Object.prototype.deep_clone = function(){
    eval("var tmp = " + this.toJSON());
    return tmp;
}
Object.prototype.toJSON = function(){
    var json = [];
    for(var i in this){
        if(!this.hasOwnProperty(i)) continue;
        //if(typeof this[i] == "function") continue;
        json.push(
            i.toJSON() + " : " +
            ((this[i] != null) ? this[i].toJSON() : "null")
        )
    }
    return "{\n " + json.join(",\n ") + "\n}";
}
Array.prototype.toJSON = function(){
    for(var i=0,json=[];i<this.length;i++)
        json[i] = (this[i] != null) ? this[i].toJSON() : "null";
    return "["+json.join(", ")+"]"
}

String.prototype.toJSON = function(){
    return '"' +
        this.replace(/(\\|\")/g,"\\$1")
        .replace(/\n|\r|\t/g,function(){
            var a = arguments[0];
            return  (a == '\n') ? '\\n':
                    (a == '\r') ? '\\r':
                    (a == '\t') ? '\\t': ""
        }) +
        '"'
}
Boolean.prototype.toJSON = function(){return this}
Function.prototype.toJSON = function(){return this}
Number.prototype.toJSON = function(){return this}
RegExp.prototype.toJSON = function(){return this}

// strict but slow
String.prototype.toJSON = function(){
    var tmp = this.split("");
    for(var i=0;i<tmp.length;i++){
        var c = tmp[i];
        (c >= ' ') ?
            (c == '\\') ? (tmp[i] = '\\\\'):
            (c == '"')  ? (tmp[i] = '\\"' ): 0 :
        (tmp[i] =
            (c == '\n') ? '\\n' :
            (c == '\r') ? '\\r' :
            (c == '\t') ? '\\t' :
            (c == '\b') ? '\\b' :
            (c == '\f') ? '\\f' :
            (c = c.charCodeAt(),('\\u00' + ((c>15)?1:0)+(c%16)))
        )
    }
    return '"' + tmp.join("") + '"';
}

测试： 

var json = {
    str : "abcde",
    num : 6,
    reg : /foobar/i,
    array : [1,2,3,4,5],
    func : function(x,y){return x+y},
    obj : {a : "b"}
}.toJSON();

alert(json);
// result
{
 "str" : "abcde",
 "num" : 6,
 "reg" : /foobar/i,
 "array" : [1, 2, 3, 4, 5],
 "func" : function(x,y){return x+y},
 "obj" : {
 "a" : "b"
}
}