如何在循环中编写此数组？

How to write this array in loop?

 $columns = array(
        "name" => 'slider'
        , "value" => $user_slider,
        "name" => 'welcomebox'
        , "value" => $user_welcomebox,
        "name" => 'servicebox'
        , "value" => $user_servicebox,
        "name" => 'postbox'
        , "value" => $user_postbox

    );

how to write name and value in loop?

Your array is wrong. You mean sub array's. Change your array, like so:

 $columns = [
    [
        'name' => 'slider',
        'value' => $user_slider
    ],
    [
        'name' => 'welcomebox',
        'value' => $user_welcomebox
    ],
    [
       'name' => 'servicebox',
       'value' => $user_servicebox
    ],
    [
        'name' => 'postbox',
        'value' => $user_postbox
    ]
];

So you can loop with foreach:

foreach ($columns as $key => $value) {
    echo $key . ': ' . $value . '<br>';
}

Are you wanting an array holding multiple users information or just one user?

You may find it useful to read up on array structure (http://php.net/manual/en/language.types.array.php) to help you move forwards, dumping the array you've created won't give you the results you're looking for.

Here's a correctly structured array which may be what you're after

$columns = array(
   'slider'     => $user_slider,
   'welcomebox' => $user_welcomebox,
   'servicebox' => $user_servicebox,
   'postbox'    => $user_postbox
);