2 replies to this topic

[jimiwa]

Hi,
I'm wondering what the $_GET function returns when the paramater
checking for being passed has not been declared or listed in the
address bar address entered.
For example
$idd = $_GET['id'];

what would the value of $idd be if in the address bar:
index.php?var1=5&var2=6

id=val
is not found ?

[Vaielab]

return nothing (well it return null)
so you should always check is the variable exist with

if (isset($_GET['id'])) {

...

}

[Alexander]

Yes, $_GET (in the appropriate CGI context) will always be an array with zero elements, so it does exist. However if you call a non-existent array index then it will return NULL (which in PHP is considered to be not set)

You can always verify these qualities yourself with the var_dump function:

<?php
  var_dump($foo['a']); //NULL, $foo does not exist
  var_dump($_GET['non-existant-id']); //NULL, $_GET exists however the id does not.
?>

This is why isset() is important.