danielbunte.de – the actionscripter » if-statements

if-statements – checking strings for being null

12 Feb, 2009 ActionScript

hello again!
Yesterday I wrote some code again and had to check if a String is null or not. The check was performed in a for-loop.
Below is some example code:

public var arrToFill:Array = [];
[... some more code here ...]
private function foo():void
{
  var i:uint;
  for( i = 0; i < 10; ++i)
  {
    if(!arrToFill[i])
    {
      arrToFill[i] = '';
    }
  }
}

This function was called different times and I wondered, that the if-statement returned false everytime.
For me it was theoretically correct that an Array-Element with a value of ” is not empty, because ” is an empty String for me, but it is something.
ActionScript3 doesn’t work like that, so for AS3 a String with a value of ” is equal to null or 0.

Conclusion:
If you have code like this and want to preallocate an element, just set it to 1. Then you can do a simpy