# What's the difference

**URL:** <https://forum.kirupa.com/t/whats-the-difference/331448>\
**Category:** Uncategorized\
**Created:** [August 2, 2013, 7:07pm UTC](https://forum.kirupa.com/t/whats-the-difference/331448 "2013-08-02T19:07:09Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![tpann](https://avatars.discourse-cdn.com/v4/letter/t/c67d28/32.png) [@tpann](https://forum.kirupa.com/u/tpann)\
**Post date:** [August 2, 2013, 7:07pm UTC](https://forum.kirupa.com/t/whats-the-difference/331448/1 "2013-08-02T19:07:09Z")

</div>

In terms of performance and/or best practices, is there any difference between these three?

```php
var arr:Array = new Array();
arr = [1, 3, 8, 9];
...or...
var arr:Array = new Array(4);
arr = [1, 3, 8, 9];
...or...
var arr:Array;
arr = [1, 3, 8 9]

```