PHP preg_replace problem

[joeyrobbo]

Hi

I'm a bit of a beginner when it comes to PHP, but am modifying a 3rd party script - but am having a problem.

Basically I want the script to rewrite certain words before publishing them on the website.

i.e.

$phrase  = "$article[description]";

$find_replace = array(
"black" => "red",
"blue" => "green"
);

$oldWord = array_keys($find_replace);
$newWord = array_values($find_replace);

$article[description2]  = str_replace( $oldWord, $newWord, $phrase );

This works fine - However I only want it to replace the first instance of the word - leaving the rest as they were - so I've tried using preg_replace instead of str_replace - but it then just displays no article at all on the website.

i.e.

$article[description2]  = preg_replace( $oldWord, $newWord, $phrase, 1 );

Tried loads of variations but it doesn't seem to want to work - Any ideas on what I'm doing wrong?

Thanks in advance, much appreciated.

[nevvermind]

You array keys need to be patterns, not just strings: '#\bword\b#' (I'm using a word boundary - \b )

$find_replace = array(
"#\bblack\b#" => "red",
"#\bblue\b#" => "green"
);

$article['description2']  = preg_replace(array_keys($find_replace), $find_replace, $article['description'], 1);

// you're using way too many variables

Also, I've found this on some forum, using substr_replace():

function str_replace_once($needle , $replace , $haystack){
    // Looks for the first occurence of $needle in $haystack
    // and replaces it with $replace.
    $pos = strpos($haystack, $needle);
    if ($pos === false) {
        // Nothing found
    return $haystack;
    }
    return substr_replace($haystack, $replace, $pos, strlen($needle));
}

[joeyrobbo]

Many thanks for this - think have now got it all sorted - thanks for your help 🙂