3v4l.org

run code in 300+ PHP versions simultaneously
<?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' ) ); $shop_name = array_column($arr2, 'shop_name', 'id'); 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);

preferences:
41.39 ms | 402 KiB | 5 Q