sub array sum

function testArray(array $array){
   sort($array);
   $max = array_pop($array);
   $arrLen = count($array);
   $len = pow(2, $arrLen);

   for($i = 0; $i < $len; $i++){
      $byte = sprintf('%0+'. $arrLen . 'b', $i);
      $cache = array();
      for($j = 0; $j <$arrLen; $j++) {
         if($byte{$j}==1 && $j!=$arrLen) {
            $cache[] = $array[$j];
         }
      }
      if($max == array_sum($cache)){
        return true;
      }
   }

   return false;
}
echo testArray(array(4, 6, 23, 10, 1, 3));
echo '<br>';
echo testArray(array(1, 22, 23, 24, 27, 29, 33));
echo '<br>';
echo testArray(array(1, 22, 23, 25, 26));
echo '<br>';
echo testArray(array(3, 5, -1, 8, 1, -2, 12));