Comments on: Javascript cloning objects

By: Praveen

Praveen — Tue, 08 Sep 2009 20:26:59 +0000

Another implementation that worked for me.

var originalJSONObj = this.jsonPanelData.fieldList; //fieldList is the json object being passed from server side
var clonedJSONObj = this.deepCloneJSON(originalJSONObj); //clonedJSONObj is the cloned object

deepCloneJSON: function(obj) {
var outpurArr = new Array();
for (var i in obj) {
outpurArr[i] = typeof (obj[i]) == ‘object’ ? this.deepCloneJSON(obj[i]) : obj[i];
}
return outpurArr;
},

By: cygro

cygro — Mon, 06 Jul 2009 09:25:14 +0000

Nice approach.
Unfortunately it works only in Firefox (breaks in Chrome, Safari and IE). Therefore useless for production use (unless you can restrict access to Firefox users only)…

By: numericalexample.com

numericalexample.com — Thu, 05 Mar 2009 10:06:28 +0000

The following function is a variant on Mikael Grave's browser independent solution with the JSON library:

By: Gareth Heyes

Gareth Heyes — Wed, 18 Feb 2009 15:26:13 +0000

@alex

It’s Firefox only

By: alex

alex — Wed, 18 Feb 2009 13:20:29 +0000

eval(uneval())
does not work for me

By: Mikael Grave

Mikael Grave — Fri, 09 May 2008 17:29:52 +0000

Your eval/uneval idea inspired me a cross-browser solution for those using YUI:

function clone = function( obj ) {
return YAHOO.lang.JSON.parse( YAHOO.lang.JSON.stringify( obj ) );
}

Tested fine with IE6 and FF2. Especially convenient for cloning arrays, hashs of arrays, arrays of hashs, etc.

Not sure about the performances. Might slow down your app if used to massively clone objects…

By: kymin

kymin — Sun, 20 Apr 2008 18:38:10 +0000

Have you not about c & c++ ’s book ?
Post my E-mail,thank you

By: Gareth Heyes

Gareth Heyes — Thu, 10 Apr 2008 17:19:09 +0000

@kourge

Nice tip and good point

By: kourge

kourge — Thu, 10 Apr 2008 17:08:44 +0000

It is bad practice to mingle with Object.prototype because it messes up property enumeration. Just google “Object.prototype is verboten” and a zillion arguments will appear. The Prototype JavaScript library once did this in 1.3 - with bad results.
The fix is to instead tack methods on to the global Object. For example:
Object.clone = function(object) { return eval(uneval(object)); };

By: Gareth Heyes

Gareth Heyes — Thu, 10 Apr 2008 12:43:31 +0000

@pdp

Damn I thought it worked in IE7 ah well neat trick anyways