将字符串连接成一个单独的字符串作为php中的变量

Question

I have a form field and would like to check for each input field if it is already exist in database.

Below is my php code:

$sql_query = "SELECT * FROM test_table";
if($result_query = $connect->query($sql_query))
{
    $items = array("firstName", "lastName", "country", "phone");

    //$names variable contains stored values which i've declared at the beginning
    $names = array($firstName, $lastName, $country, $phone);

    foreach(array_combine($items, $names) as $item => $name)
    {
        $array_items = "";
        $check_query = "SELECT $item FROM test_table WHERE $item = '".$name."'";
        $result_check_query = $connect->query($check_query);
        if($row_query = $result_check_query->num_rows)
        {
         $array_items .= $item . ", ";
        }
        echo $array_items . "gettype()=> " . gettype($array_items);
        echo "<br>";
    }
    print_r ( "<br>" . $array_items); 
}

The results from echo $array_items is as below:

The problem is when i print/echo out $array_items outside foreach loop, it only gets phone

how can i get all the individual strings as one and assigned it to a variable in php?

thanks in advance.

if there're link to old post, please provide me the link. i do not know the term use to search for this kind of problem.

Answer 1

Please try this code

$sql_query = "SELECT * FROM test_table";
if($result_query = $connect->query($sql_query))
{
    $items = array("firstName", "lastName", "country", "phone");

    //$names variable contains stored values which i've declared at the beginning
    $names = array($firstName, $lastName, $country, $phone);
    $array_items = "";
    foreach(array_combine($items, $names) as $item => $name)
    {

        $check_query = "SELECT $item FROM test_table WHERE $item = '".$name."'";
        $result_check_query = $connect->query($check_query);
        if($row_query = $result_check_query->num_rows)
        {
         $array_items .= $item . ", ";
        }
        echo $array_items . "gettype()=> " . gettype($array_items);
        echo "<br>";
    }
    print_r ( "<br>" . $array_items); 
}

The problem with your code is assignment of $array_items variable in foreach loop. Each time loop execute it set the value to blank ($array_items = "";)