Comments on: Is number odd or even?

By: JKLZ

JKLZ — Sat, 04 Oct 2008 07:39:47 +0000

there is a problem with your code. it won’t work you forgot a “)” it should have 3 of them after the H becuase you got to finish the date then the function then the if so it should look like this instead.

function is_odd($number) {
return $number & 1; // 0 = even, 1 = odd
}

if(is_odd(date(“H”))) {
print “Since it’s an odd hour, I’ve got an odd message for you: read and be happy”;
} else {
print “It’s an even hour, Steven.”;
}

By: Brad Koch

Brad Koch — Wed, 23 Jul 2008 14:20:00 +0000

You might want to consider changing this:
return $number & 1; // 0 = even, 1 = odd
to this:
return ($number & 1) ? true : false; // false = even, true = odd

Just for the sake of returning a pure boolean. Although it really shouldn’t matter in most cases.

By: David

David — Thu, 08 May 2008 18:03:17 +0000

You missed an ) on the last example

By: Cristian

Cristian — Thu, 20 Dec 2007 23:20:42 +0000

Thanks, this is really useful. Been using it for some time. is_odd() helps with creating alternate table row classes too, for SQL results and such.

By: vinay kapadia

vinay kapadia — Fri, 14 Dec 2007 19:54:39 +0000

I tried this, but I couldnt get it to work. I used:

if($number & 1)

and

if($number & 0)

and it would be all screwy, sometimes work sometimes not. The code I got to work is:

if($number % 2)

to check for odd numbers, and

if(!($number % 2))

for even numbers. I like this better cause, well, I could get it to work, and also cause it’s intuitive. Divisable by 2? then even. Not divisible by 2? then odd.

By: Nathan

Nathan — Wed, 28 Nov 2007 15:38:52 +0000

Thanks for this, a great quick answer - just what I needed

By: derek

derek — Tue, 09 Jan 2007 18:44:53 +0000

Very nice and quick lesson. Just what I was looking for