It’s a pretty usual ActionScript code excerpt:

 if (variable == true){ doSomething(); }

as you can see, the variable value is being tested here against its true value, which is a totally redundant action. A much more convenient style would be:

 if (variable){ doSomething(); }

What so nice about this solution, that it can check any variable types for valid values. Both following tests work identically :

 
var variable:Number = null;
if (variable){ doSomething(); }
 
var variable:String = undefined;
if (variable){ doSomething(); }