双层foreach循环，取出key相等的元素，组成新数组返回，如何优化成一层循环？

if($arr1 && $arr2) {

        foreach($arr1 as $key1 => $val1) {
            foreach($arr2 as $key2 => $val2) {
                if($val1['orderId'] == $val2['orderId']) {
                    $arr1[$key1]['transId'] = $val2['transId'];
                }
            }
        }
    }

回复内容：

if($arr1 && $arr2) {

        foreach($arr1 as $key1 => $val1) {
            foreach($arr2 as $key2 => $val2) {
                if($val1['orderId'] == $val2['orderId']) {
                    $arr1[$key1]['transId'] = $val2['transId'];
                }
            }
        }
    }

if($arr1 && $arr2) {
    $ids = array_column($arr2,'orderId');
        foreach($arr1 as $key1 => $val1) {
           
            if(in_array($val1['orderId'] , $ids)) {
                $arr1[$key1]['transId'] = $val1['orderId'];
            }

        }
    }

$arr1 = array(
    array(
        'orderId' => 1,
    ),
    array(
        'orderId' => 2,
    ),
    array(
        'orderId' => 3,
    ),
    array(
        'orderId' => 4,
    ),
    array(
        'orderId' => 5,
    ),
    array(
        'orderId' => 6,
    ),
);
$arr2 = array(
    array(
        'orderId' => 2,
        'transId' => 100001,
    ),
    array(
        'orderId' => 4,
        'transId' => 100002,
    ),
    array(
        'orderId' => 5,
        'transId' => 100003,
    ),
);

if( $arr1 && $arr2) {
    // `orderId` used for index
    $index_key = 'orderId';
    $column_key = 'transId';
    $columns = array_column($arr2, $column_key, $index_key);

    foreach($arr1 as &$val){
        $_key = $val[$index_key];
        if( array_key_exists($_key, $columns) ) {
            $val[$column_key] = $columns[$_key];
        }
    }

    print_r($arr1);
}