如果用户在php中的数组中，则写入日志

Question

Can anyone explain why the following isn't working?

I want to write Blocked user to log.txt if $user is in the array $blockedusers

$blockedusers = array("USER1", "USER2");
$user = "USER1";
foreach ($user as $blockedusers) {
    $file = 'log.txt';
    $current = file_get_contents($file);
    $current .= 'Blocked user' . "
";
    file_put_contents($file, $current);
}

Any ideas?

Answer 1

A loop is not required if you just want to check if a particular user is in the $blockedusers array. There's a built-in function for that purpose and it's recommended to use that.

Using in_array():

if (in_array($user, $blockedusers)) {
    $current = file_get_contents($file);
    $current .= 'Blocked user: '.$user."
";
    file_put_contents($file, $current);
}

Or, if you have an array of users, and you want to check if any of them are in the blocked list, you can do the following:

$users = array('foo', 'bar', 'baz');
foreach ($users as $user) {
    if (in_array($user, $blockedusers)) {
        $current = file_get_contents($file);
        $current .= 'Blocked user' . "
";
        file_put_contents($file, $current);
    }
}