How do I copy a JavaScript object into another object?

Question

Say I want to start with a blank JavaScript object:

me = {};

And then I have an array:

me_arr = new Array();
me_arr['name'] = "Josh K";
me_arr['firstname'] = "Josh";

Now I want to throw that array into the object so I can use me.name to return Josh K.

I tried:

for(var i in me_arr)
{
    me.i = me_arr[i];
}

But this didn't have the desired result. Is this possible? My main goal is to wrap this array in a JavaScript object so I can pass it to a PHP script (via AJAX or whatever) as JSON.

So all this sample code is in JS, right? Not PHP? In which case php's json_encode won't help you. — Tesserex
– Tesserex, Commented May 11, 2010 at 15:33
The PHP tag is actually irrelevant here. It's just a view/template technology. Writing JS code in a PHP file and having problems with JS doesn't make it a PHP problem :) — BalusC
– BalusC, Commented May 11, 2010 at 15:35

BalusC · Accepted Answer · 2010-05-11 15:29:09Z

6

Since the property name is a variable as well, the loop should look like:

for(var i in me_arr)
{
    me[i] = me_arr[i];
}

To learn more about JSON, you may find this article useful.

answered May 11, 2010 at 15:29

BalusC

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Comments

gurun8 · Accepted Answer · 2010-05-11 15:29:19Z

2

You may be looking for something as simple as json_encode

http://php.net/manual/en/function.json-encode.php

answered May 11, 2010 at 15:29

gurun8

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Comments

Jeff Fohl · Accepted Answer · 2010-05-11 15:29:47Z

1

In your code above, you are setting the me.i property over and over again. To do what you are describing here, try this:

for(var i in me_arr)
{
    me[i] = me_arr[i];
}

answered May 11, 2010 at 15:29

Jeff Fohl

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Comments

Redsandro · Accepted Answer · 2013-01-17 16:40:14Z

1

Easiest way to truly clone an object without worrying about references is

var newObj = JSON.parse(JSON.stringify(oldObj));

Very convenient, but not viable if you have functions in your objects.

edited Jan 17, 2013 at 16:40

answered Sep 4, 2012 at 14:41

Redsandro

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1 Comment

Markive Over a year ago

if you have functions in your object you will lose them with a stringify

Pointy · Accepted Answer · 2010-05-11 15:29:00Z

0

First, "me_arr" shouldn't be an Array, since you're not actually using it like one.

var me_arr = {};
me_arr.name = "Josh K";
me_arr.firstname = "Josh";

Or, shorter:

var me_arr = { "name": "Josh K", "firstname": "Josh" };

Now, your loop is almost right:

for (var key in me_arr) {
  if (me_arr.hasOwnProperty(key))
    me[key] = me_arr[key];
}

I'm not sure what the point is of having two variables in the first place, but whatever. Also: make sure you declare variables with var!!

answered May 11, 2010 at 15:29

Pointy

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Comments

Zachary · Accepted Answer · 2010-05-11 15:32:06Z

0

You should check out JSON in JavaScript. There is a download of a JSON library, that can help you build your JSON objects.

answered May 11, 2010 at 15:32

Zachary

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Comments

Felix Kling · Accepted Answer · 2010-05-11 15:33:15Z

0

Why don't you just do:

me['name'] = "Josh K";
me['firstname'] = "Josh";

?
This is the same as

me.name = "Josh K";
me.firstname = "Josh";

Read this interesting article about "associative arrays in JS".

answered May 11, 2010 at 15:33

Felix Kling

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Comments

avpaderno · Accepted Answer · 2012-08-23 00:52:16Z

0

Use json_encode() on the finished array.

edited Aug 23, 2012 at 0:52

avpaderno

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answered May 11, 2010 at 15:28

Galen

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