You shouldn't really just hide these since they often point to more serious problems. If you understand the problem it is pretty easy to avoid.
As already said above you get the error when you try to use a variable that does not exist, like
echo $nothing;
will print an
undefined variable message. You can check to see if a variable is defined using isset(), so this can use used to make sure things are defined before you use them
if (isset($nothing)){
echo $nothing;
}
this would not cause the error. Obviously if you are sure something is defined there is no point checking it so
don't do things like this
$nothing = 'something';
if (isset($nothing)){
echo $nothing;
}
It can get a bit more complicated when you assign a variable in a block for example if you assign $_GET['nothing'] to $nothing only if it's set
if (isset($_GET['nothing'])){
$nothing = $_GET['nothing'];
}
echo $nothing;
will still cause the
undefined variable error if the $_GET variable is not set. In this situation it would be better to just use $_GET directly inside the check.
A final point, where you have
//Get Album
$get_album = $_GET['album'];
You are not getting the album, you already have the album, it's stored in $_GET['album'] which you can use like any other variable
echo $_GET['album'];
