help with breaking down isset statement

[Jacquih]

I'm not sure what this statement is supposed to do:

$action = (isset($_GET['action']) && $_GET['action'] != '') ? $_GET['action'] : 'view';

Immediately after that there is a switch function:

switch ($action) {
case 'add' :
addToCart();
break;
case 'update' :
updateCart();
break;
case 'delete' :
deleteFromCart();
break;
case 'view' :

What does the isset statement do here?

Thanks for any help!

[Twey]

a ? b : c

is read as

if(a) b; else c;

although the end result is slightly different, because it can be used in expressions.
It checks to see if $_GET['action'] exists and has content. If so, it sets $action to it. Otherwise, it sets $action to "view".

[mwinter]

I'm not sure what this statement is supposed to do:

$action = (isset($_GET['action']) && $_GET['action'] != '') ? $_GET['action'] : 'view';

As you should be aware, the $_GET superglobal (associative) array contains name/value pairs present in the query string, and attempting to access an array element that doesn't exist generates a warning.

The isset function checks to see if a given element has been set to a value, returning true if it has. The following expression checks to make sure that the value isn't an empty string. Finally, the conditional expression (the ? : operator) evaluates to the value of $_GET['action'] if the other two expressions evaluate to true, or the string 'view' otherwise.

Hope that helps,
Mike

[Jacquih]

It helps alot! Thanks guys!