How to replace text with a regex pattern and integrate a counter in the replacement text?

Question

function parse($string){
    $counter = 0;
    
    $string = preg_replace("_\\[b\\](.*?)\\[/b\\]_si", \'\'. $counter .\'. $1&l         


        

Answer 1

I would solve it with a small class with the counter as property and the callback is a method of the class.

class Increaser {
    private $counter;

    public function replace($string) {
        $this->counter = 0;

        return preg_replace_callback("_\[b\](.*?)\[/b\]_si", array($this, 'createReplacement'), $string);
    }

    private function createReplacement($matches) {
        ++$this->counter;

        return ''. $this->counter .'. ' . $matches[1] . '';
    }
}