Local Variables

From ActionScriptWiki

There are some myths flying around when it comes to local variables and where they should be placed. The answer is that whenever it makes sense to put a local variable in a loop it should be done. The reason is that the ActionScript Compiler initializes all local variables at the beginning of a method and it does not matter where they have been placed in the source code.

[edit] Example

Both examples will have the same running time because the compiler will initialize n2 at the beginning of the method only once.

var n: int = 0x10;
var n2: int;
while(--n != 0)
{
	n2 = n << 1;
	trace( n2 );
}

var n: int = 0x10;
while(--n != 0)
{
	var n2: int = n << 1;
	trace( n2 );
}