Comments on: Flexible If Syntax

By: skyboy

skyboy — Fri, 06 Aug 2010 18:34:54 +0000

i’d like to point out that nicolas is wrong; the && operator evaluates both operands if the first one is true, but only the first if it is false. the || operator on the other hand would do what he said.

but for usefulness of the comma operator, in var-statements

var a:int = 15, b:Number, d:uint = uint(-1);

and if you don’t want to use the braces in a short if-block

if (value) func1(), func2(); // func1 is called, then func2 is called if value is true

though there’s hardly a use for it inside the if-statement

By: Nicolas

Nicolas — Tue, 10 Nov 2009 15:40:08 +0000

If statements are processed until a true statement is found, that is why one should put the simpler computations first.

if (simpleComputation() && complexComputation())

If simpleCompuation turns out to be true, the complexComputation won’t even be made.

By: dVyper

dVyper — Tue, 03 Nov 2009 16:48:31 +0000

What an interesting discovery! Not too useful perhaps (unless you really like obfuscated code) but still cool to know :-)

By: jackson

jackson — Mon, 02 Nov 2009 17:40:25 +0000

Yes, but it’s important to remember that all of the operands are evaluated. Consider this:

var x:int = 0;
if (x++, x++, x++)
{
}
trace(x);

Since each x++ is evaluated, the value of x is 3 at the end. The value of x is not 1 like you would expect if you thought that only the last operand was even considered.

By: Valentin

Valentin — Mon, 02 Nov 2009 10:25:06 +0000

So, the conclusion is that only the last value is used.