06 Feb 09 Tips And Tricks: Adobe Flex – avoid accessing null objects

One of the many possible ways of iterating over an array in Flex is:

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private function iterateOverArray(arr : Array) : void {
  for(var i : int = 0; i < arr.length; i++){
    doSomethingWith(arr[i]);
  }
}

But this code will cause problems if the Array is null, to avoid this kind of problems you can use the following code instead:

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private function iterateOverArray(arr : Array) : void {
  for each(var o : Object in arr){
    doSomethingWith(o);
  }
}

This way we do not need two variable declarations, and we do not try to read the length of a possible null variable.

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Tags: b02, flex, tips