javascript array push value of object

Question

I am trying to create an array of objects, however when I am pushing onto my array it is adding a reference to the object rather than copying the values.

var nestedOrgList = [];
var tempTopOrg = {};

var i = 0;
while (typeof divList[i] !== 'undefined') {
    tempTopOrg.org = divList[i++]; // increment i after we assign this
    tempTopOrg.suborgs = [];

    while ($(divList[i]).has('.expand').length < 1 && i < divList.length) {
        tempTopOrg.suborgs.push(divList[i++]);
    }

    nestedOrgList.push(tempTopOrg);
};

Is there a better way to do this? Or do I need to do a manual copy?

nestedOrgList[insertIndex].org = tempTopOrg.org;
// etc..
insertIndex++;

@NuclearGhost JavaScript passes *values* (hint: objects *are* values) and, just like during an assignment, those *values* are *not* copied/cloned/duplicated in the process. There is *no* use of "reference" describing this behavior in the ECMAScript specification. — user2864740, Jan 28 '14 at 02:01

score 2 · Accepted Answer · edited May 23 '17 at 12:18

2

You can check the following answer

How do I correctly clone a JavaScript object?

The JSperf

http://jsperf.com/cloning-an-object/82

definitely JavaScript should have a way natively to copy references.

edited May 23 '17 at 12:18

Community

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answered Jan 28 '14 at 01:58

bipsa

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Thank you for the reference to that answer – Troy Cosentino Jan 28 '14 at 02:28

score 0 · Answer 2 · answered Jan 28 '14 at 01:53

0

A common method if speed is not a critical goal is to encode/decode the object using JSON:

var json = JSON.stringify(tempTopOrg);
nestedOrgList.push( JSON.parse(json) );

answered Jan 28 '14 at 01:53

Matt

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score 0 · Answer 3 · edited May 23 '17 at 10:29

0

javascript passes objects and arrays by reference, so you will have to make a copy before pushing,

myarray.push(JSON.parse(JSON.stringify(obj)));

is quick and dirty and probably has performance issues,

this question tries to tackle cloning of objects.

edited May 23 '17 at 10:29

Community

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answered Jan 28 '14 at 01:53

Patrick Evans

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score 0 · Answer 4 · answered Jan 28 '14 at 02:06

0

to make a deep copy use

var newcopy = temp.slice(0);

and to filter undefined and null values use

newcopy  = newcopy.filter(function(e){ return e });

answered Jan 28 '14 at 02:06

MZH

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javascript array push value of object

4 Answers4