Online PHP editor | refs for dpPss

<?php $first = array( 2, 3, 5, 7); $second = array(2, 3, 5, 23); $prime = "Prime Factors of 420:"; $scndprim = "Prime Factors of 690:"; foreach ($first as $key => $value) { if(in_array($value, $second)) { $prime .="<b>".$value."</b>,"; }else{ $prime .=$value.","; } // ========= for second array if(in_array($second[$key], $first)) { $scndprim .="<b>".$second[$key]."</b>,"; }else{ $scndprim .=$second[$key].","; } } print_r(trim($prime,',')); print_r(trim($scndprim,','));