ClearPar.php

<?php
/**
 * Class for extract chars paring
 * Support: 
 *        On PHP 5.x
 * Execution using:
 * - From Code Inside, instance from Class:
 *       $cp = new ClearPar();
 *        echo $cp->build('(()()()()(()))))())((())');
 */
class ClearPar
{
    var $outputString = '';
    function __construct()
    {
    }

    /**
    * Extract chars paring
    */
    function build($inputString = null)
    {
        preg_match_all('/\(\)/', $inputString, $matching, PREG_OFFSET_CAPTURE);
        if (count($matching[0]) > 0)
        {
            foreach ($matching[0] as $k => $v)
                $this->outputString .= substr($inputString, $v[1], 2);
        }

        return "Input String:\n" . $inputString . "\n\n\n" . 
                "Result:\n" . $this->outputString;
    }
}

$cp = new ClearPar();
echo $cp->build('aognn *236 (()()()()(()))))())((()) asj');
?>