Test for even number?

Nixon

Hi all,

is there a way to test for an even number?

Or if there is an easy way to alternate row colours in a table without checking for even numbers.

Thanks. Jack

laserlight

$num % 2 == 0 <=> $num is even

Though there are also the bitwise operators (which can speed up the checking), but I think PHP treats them a little differently from what I'm used to in C++.

eoghain

Here is the standard:

if ($num % 2)
{
   // Odd Row
}
else
{
  // Even Row
}

Since 0 is returnd from the modulus operator when you divide an even number by 2 and since if reads 0 as false this code does exactly what you want.

Nixon

Sorry, searched for it in the forums 🙁 and I manipulated a piece of code I found, this is my final piece:


if ($colour=="#E8E8E8") { print "<tr>"; $colour=NULL; } else { print "<tr bgcolor='#E8E8E8'>"; $colour="#E8E8E8"; }

laserlight

If you're still interested in a function to determine if an integer is even or odd:

function isEven($num) {
	if ($num & 0 == 0)
		return false;
	else
		return true;
}

The method that you found should be usable, though checking for even numbers is also viable.

Weedpacket

For amusement, there are half a dozen or so other methods in this thread.