Purpose of PHP use keyword in array_map() function?

Question

I've the following code of lines in my application. Can anybody please tell me what is the purpose of use keyword in the following array_map() function?

array_map( function($record) use ($edit_form, $otherfields, $otherfields_keys)
{
    User::parseData($record, $edit_form['metadata']);

    if (isset($otherfields[$record['user_id']])) {
        return $record + $otherfields[$record['user_id']];
    }

    return $record + $otherfields_keys;

}, $records);

Thanks in advance.

Answer 1

The callback passed to array_map() doesn't have access to outside variables so they must be passed using use.

You can read more about anonymous functions in the PHP documentation.