Round down to nearest half integer in PHP

Question

I'm pulling my hair out here, so any help would be greatly appreciated. I need a php function that will take a float and round it down to the nearest half (x.0 or x.5). I found other functions that will round to the nearest fraction, but they round both ways.

The function I need can only round down.

Examples:

7.778 = 7.5

7.501 = 7.5

7.49 = 7.0

7.1 = 7.0

Thanks!

Answer 1

Floor won't help for fractions. I think you're looking for round() in PHP_ROUND_HALF_DOWN mode with the precision upped a bit?

http://www.php.net/manual/en/function.round.php

Answer 2

$x = floor($x * 2) / 2;

Answer 3

I'm assuming PHP has a floor function: floor($num * 2) / 2 ought to do it.