How to correctly implement PHP to generate unique identifiers_PHP Tutorial

What we want to introduce to you in detail today is the code example of

PHP generating unique identifier:

1. < ?
2. //Generate unique identifier
3. //sha1() function, "Secure Hash Algorithm (SHA1)"
4. function create_unique() {
5. $data = $_SERVER['HTTP_USER_AGENT'] . $_SERVER['REMOTE_ADDR']
6. .time () . rand();
7. return sha1($data);
8. //return md5(time().$data) ;
9. //return $data;
10. }
11. ?>

PHP generate unique identifier function description and examples