I've been attempting to figure out the background math in a Flash game by using the Sothink SWF Decompiler to view the ActionScript files. Admittedly I know very little about ActionScript, but I'm seeing lines of code that look like:
_loc_2 = null * (null * true) <= null;
or:
_loc_3 = null & null << (null === false);
From where I stand, value <= null doesn't make much sense, and neither does null * true or null & null. Am I just not understanding ActionScript properly, or is this an error in the decompiling process? If it's an error, is there any way to solve it?
The swf has probably been encrypted with an obfuscater, which is why you're seeing nonsense like this. You can test this code yourself (though you have to compile in non-strict mode):
trace( "null & null: " + ( null & null ) ); // traces 0
trace( "null === false: " + ( null === false ) ); // traces false
trace( "null & null << (null === false): " + (null & null << (null === false)) ); // traces 0
trace( "null * true: " + ( null * true ) ); // traces 0
trace( "null * null * true " + ( null * ( null * true ) ) ); // traces 0
trace( "null * (null * true) <= null: " + (null * (null * true) <= null) ); // traces true
so basically _loc_2 is a local variable set to 0, while _loc_3 is a local variable set to true