php preg_replace or expression replace all but first match-CodePudding

Hi guys could you please help me to resolve this riddle?

I have an array of keywords pretty big one that I use to match those keywords in content.

Example: $array('game','gamers','gaming'); etc...

I am using this foreach method to loop though each keyword and match it against content but in some cases content can be really big and more than 50 keywords and more than 20 posts per page slows the site down dramatically.

foreach($array as $key => $vall)
{

$pattern = '/\b'.$vall.'\b/';

$data['content'] = preg_replace($pattern, " <a style=\"font-weight: bold;color:rgb(20, 23, 26);\" href=\"".$url."\">".$vall."</a>", $data['content'],1);    
}

The good thing about is that I can specify replace limit to one means that it will not replace all instances of that keyword.

The method above is not performance effective.

My other approach is this but there is an issue. I can't specify limit.

$pattern = '/\bgamers|gaming|gamer\b/';
$data['content'] = preg_replace($pattern, " <a style=\"font-weight: bold;color:rgb(20, 23, 26);\" href=\"".$url."\">$0</a>", $data['content']);

The method above works great but it replaces all instances of matched keywords.

Question. How can I add to pattern keywords separated by or expression and then replace only first match of each keyword.

Update.

$string = 'I am a gamer and I love playing video games. Video games are awesome. I have being a gamer for a long time. I love to hang-out with other gamer buddies of mine.';

$keyWordsToMatch = 'gamer,games';

For the output it needs to replace only forst instance of $keyWordsToMatch.

Like this:

$string = 'I am a (gamer)_replace and I love playing video (games)_replace. Video games are awesome. I have being a gamer for a long time. I love to hang-out with other gamer buddies of mine.';

CodePudding user response：

I think you can solve this by using preg_replace_callback and keeping track of keywords you found. I've also added the grouping the @Wiktor Stribiżew suggested, and I personally like to use named-captures in RegEx.

See the comments for additional details

$string = 'gamer thing gamer games test games';
$pattern = '/\b(?<keyword>gamer|games)\b/';

// We'll append to this array after we use a given keyword
$usedKeywords = [];
$finalString = preg_replace_callback(
    $pattern,

    // Remember to capture the array by-ref
    static function (array $matches) use (&$usedKeywords) {
        $thisKeyword = $matches['keyword'];
        if (in_array($thisKeyword, $usedKeywords, true)) {
            return $thisKeyword;
        }

        $usedKeywords[] = $thisKeyword;
        
        // Do your replacement here
        return '~'.$thisKeyword.'~';

    },
    $string
);

print_r($finalString);

The output is:

~gamer~ thing gamer ~games~ test games

Demo here: https://3v4l.org/j40Oq