PHP Switch ID error in Navigation - php

Question

I’m working on a site and I kept getting a
Notice: Undefined index: id in file root on line 3
I know its something simple but can’t figure out where the problem lies exactly.
here is the code:
<?php
switch($_GET['id']) {
default:
include('pages/hello.php');
break;
case "testimonials":
include('pages/testimonials.php');
break;
case "faq":
include('pages/faq.php');
break;
case "raq":
include('pages/raq.php');
break;
case "contact":
include('pages/contact.php');
break;
}
?>
line 3 would be <?php switch($_GET['id']) {
any help would be greatly appreciated!

Answer 1

This is because in your url id=x is not always set, so when your trying to switc hthe value its not there. what you should do is like so:
<?php
$id = isset($_GET['id']) ? $_GET['id'] : ''; //This is just a short if-else
switch($id)
{
default:
include('pages/hello.php');
break;
case "testimonials":
include('pages/testimonials.php');
break;
case "faq":
include('pages/faq.php');
break;
case "raq":
include('pages/raq.php');
break;
case "contact":
include('pages/contact.php');
break;
}
?>
Basciall $id = isset($_GET['id']) ? $_GET['id'] : ''; what this says is, IF id is within the url then use that, otherwise use an empty string, the reason for the empty string is it will trigger the default: within the switch statement
this way $id will always be set to something.

Answer 2

Make sure that id is set and the default should go at the end:
if (!isset($_GET['id'])) {
include('pages/hello.php');
}
else{
switch($_GET['id']) {
case "testimonials": include('pages/testimonials.php'); break;
case "faq": include('pages/faq.php'); break;
case "raq": include('pages/raq.php'); break;
case "contact": include('pages/contact.php'); break;
default: include('pages/hello.php'); break;
}
}
For security reasons, make sure to sanitalize yor $_GET['id']. I would suggest you to setup an array of allowed pages and include those that are in the array. You can use in_array function for that.

Answer 3

It seems that the url parameter 'id' is not defined, that's the cause of the notice.
You should first check for its existence, eg.
if (isset($_GET['id'])) {
your code here
}