CODEWITHSUNDEEP
javascript
Seho Lee
Seho Lee

Reputation: 4108

referencing variable in javascript

var items = new Array("one", "two", "three");
var itemsRef = items;
items.push("four");
console.debug(itemRef);
console.debug(items);

I really dont get the idea how above items and itemsRef are same even items added "four" when after itemsRef referenced items. Isn't it reasonable that itemsRef should have only ("one" "two" "three")?

If itemsRef keep pointing items forever, why do we use such an useless argument like items = itemsRef? I am still not getting the idea. Can anybody tell me how this is works and why JavaScript let variables pointing each other forever?

Upvotes: 1

Views: 89

Answers (2)

MK_Dev
MK_Dev

Reputation: 3343

In this case itemsRef is not pointing at items, but rather at the object (array) items reference is pointed at. In other word, items and itemsRef point to the same object and not each other.

Upvotes: 1

Marc
Marc

Reputation: 11633

Javascript makes assignments of Objects and Arrays by reference instead of by value/copy. That's why you're seeing that behavior. There's plenty of web documentation about that.

But if your goal is to copy an array, do this:

var newArray = oldArray.slice(0);

Upvotes: 4

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