Question

I have a text that contains usernames prepended with @ symbol. Example:

One day @john decided to ask @jane out.

I want to replace all occurances of the usernames with a link, for the sake of an example lets say I would want to replace @user with link-user, Example:

One day link-john decided to ask link-jane out.

This can be done with following command:

preg_replace('`@([a-zA-Z0-9]{2,15})`', 'link-$1', $text);

Additionally I would like to obtain an array of all the matches like preg_match would have done, but I am unable to, because preg_replace does not seem to provide that array. What is the most efficient way to accomplish this? I feel like doing preg_match and later preg_replace would be a waste of resources, would it not?

If you feel there is a better way to accomplish this, I would appreciate your feedback.

Thanks!

Answer 1

You can use preg_replace_callback:

<pre>
<?php

$arr = array();

function linker( $matches ) {
    global $arr;
    $arr[] = $matches[1];
    return "link-{$matches[1]}";
}

$text = "One day @john decided to ask @jane out.";
$result = preg_replace_callback('`@([a-zA-Z0-9]{2,15})`', "linker", $text);

echo $result . "\n";    
print_r( $arr );
?>
</pre>

Result:

One day link-john decided to ask link-jane out.
Array
(
    [0] => john
    [1] => jane
)

If you are using PHP 5.3, you can make this much cleaner with anonymous functions.