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Ken Chung
17,585 PointsWhat isset() function exactly do in PHP? Is it really necessary to use in the "Build a Basic PHP Website" project?
Hi everyone,
I'm currently doing the "Build a Basic PHP Website" course and I'm seeing Alena use the isset function, she says that we need to use it to do another check? Why do we need to do another check? I'm trying out the code without the isset() function and it still works fine the way it is, what's the difference?
1). What is it exactly used for?
2). Do you have to use it?
3). When is it good practice to use it?
Thanks!
2 Answers
suyash patankar
2,310 PointsHello yes it is necessary to make another check, because if you see carefully you will find that in header.php we are passing category through URL using <a href="">
<ul class="nav"> <li class="books"><a href="catalog.php?cat=books">Books</a></li> <li class="movies"><a href="catalog.php?cat=movies">Movies</a></li> <li class="music"><a href="catalog.php?cat=music">Music</a></li> <li class="suggest"><a href="suggest.php">Suggest</a></li> </ul>
BUT WHAT IF A PAGE DOES NOT HAVE CATEGORY SET IN <a href="">??? IN THAT CASE OUR if-else STATEMENTS IN catalog.php WILL NEVER BE EXECUTED AND WE WILL GET UNDEFINED INDEX ERROR, to demo this please comment isset function and run http://port-80-ncrrxw2vyd.treehouse-app.com/catalog.php
It is necessary to use it to avoid any undefined index error
suyash patankar
2,310 PointsHi @Iain Simmons I will try that way, thank you very much for the help.
Iain Simmons
Treehouse Moderator 32,305 PointsIain Simmons
Treehouse Moderator 32,305 PointsHi suyash patankar, unfortunately you can't link to files in one of your Workspaces directly. Instead, you would need to share a Snapshot of your workspace, and Ken Chung would need to 'Fork' it to use/test that code.