Sessions in PHP, what's the problem?

Question

PHP

I don't know how to elaborate my question, but I'll try.
I want to make it so that in the form input field (input value) the information entered by the user after updating the page is saved and displayed, for this I used the following code

<input type="text" name="username" value="<?=$_SESSION['reg']['username'];?>"/><br /> 
<input type="text" name="name" value="<?=$_SESSION['reg']['name'];?>"/><br />

etc.
Everything is saved and displayed normally, but the problem is that initially when we go to the registration page, an error is displayed in the input field (see photo) , and I need it to be empty.
PS I apologize if it is unclear described the problem, but please help those who understand what the point is.

Answer 1

Bad but working option:

<input type="text" name="username" value="<[email protected]$_SESSION['reg']['username'];?>"/><br /> 
<input type="text" name="name" value="<[email protected]$_SESSION['reg']['name'];?>"/><br />

I'll just hint at a good one:

$username = '';
if (isset($_SESSION['reg']['username'])) {
    $username = $_SESSION['reg']['username'];
}

Answer 2

turn off the display of NOTIS in the production version and there will be no problems.
In short - a call to an unknown variable, you need to initialize before you output.
you can check - if there is $_SESSION['reg']['username'] - output it, otherwise empty

Answer 3

did you try to initialize it on the server before showing the form and fill it with empty lines?)

Answer 4

Use this
Source function here: stackoverflow.com/questions/9555758/php-default-ar...

function get(&$var, $default=null) {
    return isset($var) ? $var : $default;
}

$test = array('foo'=>'bar');
get($test['foo'],'nope'); // bar
get($test['baz'],'nope'); // nope
get($test['spam']['eggs'],'nope'); // nope
get($undefined,'nope'); // nope