Online PHP editor | output for ULCvX

<?php $arr = array( array( 'id' => 1, 'user_name'=>'test1' ), array( 'id' => 2, 'user_name'=>'test2' ), array( 'id' => 3, 'user_name'=>'test3' ) ); $arr2 = array( array( 'id' => 1, 'shop_name'=>'shop1' ), array( 'id' => 5, 'shop_name'=>'shop2' ), array( 'id' => 3, 'shop_name'=>'shop3' ) ); /*function filter($item) { return count($item) == 3 ? $item :false; } $newArr = array_filter(array_merge($arr, $arr2), 'filter'); print_r($newArr); foreach($arr as $key => &$value) { //$value['shop_name']=''; } unset( $value ); foreach($arr as $k2 =>&$v2) {$v2['shop_name']=''; foreach($arr2 as $k =>$v) { if($v2['id'] == $v['id']) { $v2['shop_name'] = $v['shop_name']; } } } print_r($arr);*/ $shop_name = array(); foreach($arr2 as $item) $shop_name[$item['id']] = $item['shop_name']; foreach($arr as $key => $item) { $exist = array_key_exists($item['id'], $shop_name); $arr[$key]['shop_name'] = $exist ? $shop_name[$item['id']] : ''; } print_r($arr);