Javascript scope - Need to preserve original value

Asked Jun 13 '15 at 15:22

Active Jun 13 '15 at 15:25

Viewed 23 times

var oldArray = [],someArray=[],newArray=[];

oldArray = [4,5];
someArray =[1,2,3]; 
newArray = someArray;

for (var i=0; i<oldArray.length; i++){
    someArray.push(oldArray[i]);
}

// I want this to be [1,2,3] but it becomes [1,2,3,4,5]
// due to scope issue I believe
oldArray = newArray;

newArray needs to be original someArray of [1,2,3] when oldArray = newArray, however due to scoping by the time that oldArray = newArray it becomes [1,2,3,4,5] instead.

How can I solve this issue? I need to preserve original someArray value and assign those values into oldArray.

edited Jun 13 '15 at 15:25

uraimo

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asked Jun 13 '15 at 15:22

whtflower

2

This isn't a scope issue. – Matt Ball Jun 13 '15 at 15:25
Matt, could you point to me a other posting that I can look if you think it's duplicate? I did some stackoverflow search and couldn't find the solution what I am having an issue. – whtflower Jun 13 '15 at 15:28
Scroll up. It's at the top of your post now. – Matt Ball Jun 13 '15 at 15:29
@whtflower if you want to create a real copy of an array, don't assign it, use `slice` instead: `var newArray = someArray.slice(0)` – uraimo Jun 13 '15 at 15:29
http://stackoverflow.com/a/7486130/4989460 – stdob-- Jun 13 '15 at 15:32

Javascript scope - Need to preserve original value

0 Answers0