php verification username problem

PHP username verification must be within 5 to 15 characters, and can only be letters, numbers, and underscores

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PHP username verification must be within 5 to 15 characters, and can only be letters, numbers, and underscores

You can use regular verification, refer to the following

<code>/**
 * description 用户名验证
 */
final public static function isName($val) {
    try {
        $pattem = "/^[a-zA-Z0-9_]{5,15}$/";
        if (preg_match ( $pattem, $val )) {
            return $val;
        } else {
            return false;
        }
    } catch ( Exception $e ) {
        throw $e;
    }
}</code>

Regular Expressions

<code>(\w|\d){5,15}/u</code>

In fact, all regular rules can be used universally~ It’s just that the calling method is different~ The rules I wrote in Swift are the same as those written in the front end, but the final judgment method of calling is different~