test_preg_replace

<?php

$string = 'The quick brown fox jumps over the lazy dog.';

$patterns = array();

$patterns[0] = '/quick/';

$patterns[1] = '/brown/';

$patterns[2] = '/fox/';

$replacements = array();

$replacements[2] = 'bear';

$replacements[1] = 'black';

$replacements[0] = 'slow';

echo preg_replace($patterns, $replacements, $string);

?>