isset php函数检查字符串长度

Question

in my website's registration form, the following php code controls user first name field :

if (!isset($value[4])){
    $return = $register_msg['_register_some_msg'];
} 

what does this code do ? does it have anything with checking the string length ? currently it forces the first name of minimum 3 characters, but as i searched seems that strlen() Function checks the length of string which doesn't exists there.

Answer 1

The isset() method here just verify if $value[4] (your object, or string, or other) exists or not.