CODEWITHSUNDEEP
javascriptjquery
Vassilis Barzokas
Vassilis Barzokas

Reputation: 3252

Copy object properties to a new one - not by reference

I have a JavaScript array of objects, which is initialised with some values. I want to copy those values to a new array of objects, but without referencing to the original one, so I can then manipulate the new object.

I tried objectOptions.concat() like in this sample code but it then deletes also the referenced original object:

var objectOptions = [{option1: 'value1', someOption: 'value2'}];

function objectClean(){
    var newObjectOptions = objectOptions.concat();

    for(var i in newObjectOptions ) {
        delete newObjectOptions[i]['someOption'];
    }

    return newObjectOptions ;
};

Upvotes: 0

Views: 125

Answers (2)

bfavaretto
bfavaretto

Reputation: 71939

If your object is simple enough and JSON-compatible (i.e., only contains objects, arrays and primitives, no DOM references, no Regex objects, no circular references etc.), the simplest way to clone is:

var clone = JSON.parse(JSON.stringify(original));

Otherwise, you'll need a deep copy function, like the one found on this answer*:

function clone(obj){
    if(obj == null || typeof(obj) != 'object')
        return obj;

    var temp = obj.constructor(); // changed

    for(var key in obj)
        temp[key] = clone(obj[key]);
    return temp;
}

* Be careful! The accepted answer to that question is a jQuery only solution, and terribly overrated!

Upvotes: 3

Patt Mehta
Patt Mehta

Reputation: 4204

var copyme = {/*object with properties which are to be copied in another object*/};
var copy = {};
for (var attr in copyme) {
  if (copyme.hasOwnProperty(attr)) copy[attr] = clone(copyme[attr]);
}

Upvotes: 1

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