How can I go about removing the error message "Undefined Index" for $

How do I get rid of the error message at the start of this code? I recognize and understand why the message is popping up, but I'm either not being clever enough, need to go to sleep, or both, as I can't figure out what the best way to remove the error is.

The error in question: Undefined index: username in C:\xampp\htdocs\login\login.php on line 4

Until the $_POST["username"] variable is defined when you hit "login" it stays at the top of the page. How can I go about repairing this code?

Here is the GitHub full code: https://github.com/TakingJester766/PHPLogin/blob/main/login.php

CodePudding user response：

You shouldn't access $_POST until it's actually defined. To do that you can do something like:

if (isset($_POST["username"])) {
  $logged_user = $_POST["username"];
}

CodePudding user response：

You have to check if the value set example:

if (isset($_POST["username"])) {
   $logged_user = $_POST["username"];
} else {
   //error Messsage or nothing
}