Notice About not Defined Index with Login Form

[Glese]

<?php

$user_name = 'bazarr';
$user_password = '*******';


if($_POST['user_name'] != $user_name || $_POST['user_password'] != $user_password) {

?>

<h3>The Login</h3>
<form method="post" action="">
    <input type="text" name="user_name" />
    <input type="password" name="user_password" />
    <input type="submit" name="blog_creation_login_submit" value="Submit" />
</form>

<?php
} else {
?>




<h3>The Article</h3>

 

With the above script I am getting following notice:

 

Notice: Undefined index: user_name

 

It is regarding the user name variable, my question is how to solve this one and avoid the notice?

[PFMaBiSmAd]

The same way someone suggested in one of your previous threads - http://www.phpfreaks.com/forums/index.php?topic=349042.msg1646845#msg1646845

[KevinM1]

You avoid the notice by checking to see if the variable exists. 

 

Index, in this context, means array index.  The array in question is $_POST.  It's telling you that $_POST['user_name'] doesn't exist; or, more specifically, 'user_name' is an undefined index because it wasn't set during the POST because whatever form input it's supposed to come from was empty.

 

So, you need to ensure that the variable exists by checking either isset or empty before attempting to use it in another way.

[Glese]

I got it to work.

 

Thanks kevin for the explanation, this part of PHP is confusing me a bit.