PHP - Undefined index - $_POST hidden input

Question

I'm a beginner at coding, and I have to make a small game in php for school. I have to use a hidden input, like this:

<form action="process.php" method="post">
<input type="hidden" name="rand" value="<?php rand(1,10); ?>" />
</form>

The value stands for a random number between 1 and 10 (I hope the value is correct). Now, in process.php I want to retrieve the random number by using post, so what I tried to do is the following:

<?php $random = $_POST['rand'];
echo $random; ?>

In my browser (Firefox), I'm getting the following error:

Notice: Undefined index: rand in G:\xampp\htdocs\process.php on line 2

Does anyone know how I can echo the hidden value without using complex techniques?

Thanks in advance, Maxime

hidden inputs only get processed *after* the form was submitted. — Funk Forty Niner, Mar 20 '16 at 16:24
possible duplicate of [PHP: Notice: Undefined variable and Notice: Undefined index](http://stackoverflow.com/questions/4261133/php-notice-undefined-variable-and-notice-undefined-index) — Funk Forty Niner, Mar 20 '16 at 16:27
Is your form also in `process.php`? If yes, then is this error message on initial page load? — Sean, Mar 20 '16 at 16:30
no, I only echoed the hidden value in process.php, and the error was on the initial page load — Maxime D'Haese, Mar 20 '16 at 17:14

Indrasis Datta · Answer 1 · 2016-03-20T16:36:01.000

1

You haven't echoed your rand function within the hidden input tag.

Also, there should be a submit button. Only then you can access the POST parameters.

<input type="hidden" name="rand" value="<?php echo rand(1,10); ?>" />
<input type="submit" name="submit" value="submit">

Try something like this:

if (isset($_POST['submit'])) {
   echo "<pre>";
   print_r($_POST); // See your POST array
   $random = $_POST['rand'];
   echo $random;
}

Hope this helps.

Peace! xD

edited Mar 20 '16 at 16:36

answered Mar 20 '16 at 16:27

Indrasis Datta

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I think you made a small mistake there ;) "

 instead of "". But anyway, thanks a lot!

– Maxime D'Haese Mar 20 '16 at 16:33

PHP - Undefined index - $_POST hidden input

1 Answers1