Here's one way to do it in PHP. There are possibly better ways. 

#!/usr/bin/php -q

<?php

error_reporting(E_ALL);

$data = array("one", "foo", "two", "foo", 
              "three", "foo", "four", 
              "foo", "foo");

$changed = 0;

$new = preg_replace_callback("/foo/", 
        create_function(
               '', 
               '$GLOBALS{"changed"}++; 
                return "bar";'
        ), 
         $data);

print_r($new);

print "We changed $changed items\n";
?>

[download]

This prints

Array
(
    [0] => one
    [1] => bar
    [2] => two
    [3] => bar
    [4] => three
    [5] => bar
    [6] => four
    [7] => bar
    [8] => bar
)
We changed 5 items

[download]

I hope this helps satisfy your curiosity

In reply to Re^3: Stupid mistakes I repeatedly make by thinker
in thread Stupid mistakes I repeatedly make by brian_d_foy

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