Javascript pass by reference

Question

How can I capture the value of an object at the current state of the line of code and use that value later instead of the reference?

How can I keep the value of myRows as 1 so I can use it for comparison??

var myRows= this.grid.getSelectedRows();  // 1
var newRows= myRows;

  //run some logic to add 8 to newRows


 alert(myRows)  // 9

 alert(newRows)  //9

if myRows != 1 in your alert, then you must of changed it in your some logic or else it would still be 1 assuming getSelectedRows returns 1 — Huangism, Mar 06 '14 at 18:49
I don't see how "pass by reference" has anything to do with this; there are no values being "passed" anywhere, unless I'm missing something. — Pointy, Mar 06 '14 at 18:49
@RocketHazmat I could've sworn that's how I read it the first time, but I kept re-reading it and confused myself. — Ian, Mar 06 '14 at 18:54
@Ian: If that's the case, then this makes no sense. I was wondering if it was an object, an array, or actually a number. — gen_Eric, Mar 06 '14 at 18:56
What does `console.log(myRows)` show you? Is it an array or an object? Or is it a number? — gen_Eric, Mar 06 '14 at 18:57
Show us the "some logic" part. If myRows was 1 string or number and your 'some logic' did not change it, then the alert should show 1 — Huangism, Mar 06 '14 at 18:58

score 0 · Answer 1 · answered Mar 06 '14 at 18:53

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You need to copy each of the attributes of the object recursively.

The easiest way is to just use some framework like lodash or angularjs.

answered Mar 06 '14 at 18:53

plc

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score 0 · Accepted Answer · edited May 23 '17 at 10:31

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My suggestion is that you make a deep copy of your JavaScript object. This is usually referred to as cloning an object.

See What is the most efficient way to deep clone an object in JavaScript? on various methods how to achieve this.

edited May 23 '17 at 10:31

Community

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answered Mar 06 '14 at 18:56

mvw

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Javascript pass by reference

2 Answers2