Question

Maybe this is a stupid question but what is faster?

<?php

function getCss1 ($id = 0) {
    if ($id == 1) {
        return 'red';
    } else if ($id == 2) {
        return 'yellow';
    } else if ($id == 3) {
        return 'green';
    } else if ($id == 4) {
        return 'blue';
    } else if ($id == 5) {
        return 'orange';
    } else {
        return 'grey';
    }
}

function getCss2 ($id = 0) {
    $css[] = 'grey';
    $css[] = 'red';
    $css[] = 'yellow';
    $css[] = 'green';
    $css[] = 'blue';
    $css[] = 'orange';
    return $css[$id];
}

echo getCss1(3);
echo getCss2(3);
?>

I suspect is faster the if statement but I prefere to ask!

Answer 1

getCss1 (if statements) is roughly twice as fast getCss2 (array access) from my benchmarks.

Results from microtime():

getCss1 called 10,000 times in 0.016569852828979 seconds
getCss2 called 10,000 times in 0.037255048751831 seconds

Per the comments, I agree about maintainability of using a translation array. Accessing $css directly is significantly faster given the removal of function overhead and array redeclaration.

getCss1 called 10,000 times in 0.016607999801636 seconds
$css accessed 10,000 times in 0.0026898384094238 seconds

Note: Running PHP 5.3.15 on Mac OS X 10.8. I also varied call order $id to test execution paths.