How to convert binary to decimal without using PHP native functions?

Question

My code is like this :

Answer 1

Here is in http://php.net/manual/en/function.bindec.php#44910

function reconvert($bin_nr) {
 $base=1;
 $dec_nr=0;
 $bin_nr=explode(",", preg_replace("/(.*),/", "$1", str_replace("1", "1,", str_replace("0", "0,", $bin_nr))));
 for($i=1; $i<count($bin_nr); $i++) $base=$base*2;
 foreach($bin_nr as $key=>$bin_nr_bit) {
     if($bin_nr_bit==1) {
         $dec_nr+=$base;
         $base=$base/2;
     }
     if($bin_nr_bit==0) $base=$base/2;
 }
 return(array("string"=>chr($dec_nr), "int"=>$dec_nr));
}

Check here : https://eval.in/556903