Is it best to define a variable when using the same $_GET key multiple times?

Question

In multiple place on a script I have ...

if (isset($_GET['event-id']) { ... }

Would it slow things down to call the key twice? Should I just define a new var like ...

$event_id = $_GET['event-id']; if ($event_id) { ... }

techierishi · Accepted Answer · 2015-10-06 05:45:52Z

You should always go with second approach

$event_id = $_GET['event-id']; if ($event_id) { ... }

It will not slow things but suppose in the future 'event-id' changes then you will have to change it every where which will be a heavy task to do.

Ormoz · Accepted Answer · 2015-10-06 05:54:59Z

This also raise an E_NOTICE if $_GET['event-id'] is not set:

$event_id = $_GET['event-id'];

I prefer

$event_id = isset($_GET['event-id']) ? $_GET['event-id'] : false;

especially when I am going to use $event_id multiple times. Then, I can write:

if($event_id){ //do your code }

or in cases that an empty $event_id is possible:

if($event_id !== false){ //do your code }

danopz · Accepted Answer · 2015-10-06 05:43:33Z

The best would be to assign this onto a var and validate it before all further processing, to get sure this var contains no prohibited content.

I don't think it would slow down as it's only a Array call, but it is a security gap.

Edit:

Also if it isn't set you could define a default value.

Suyog · Accepted Answer · 2015-10-06 05:46:35Z

If there is really a need to check $_GET['event-id'] at many places in your code, you can set it once using Ternary Operator

$event_id = isset($_GET['event-id']) ? $_GET['event-id'] : '' ;

Then you can use it like if ($event_id) or if(empty($event_id)) or if(!empty($event_id)) depending upon your need of condition.

4 Answers 4