Comments on: isset vs. empty

By: Victor

Victor — Sat, 15 Jan 2011 20:20:54 +0000

Good article. Just found another over at Tutorial Arena that takes a more in depth look at the difference between the two: PHP isset vs empty Hope these 2 articles help someone.

By: Lenny

Lenny — Sun, 05 Dec 2010 13:47:01 +0000

Great advise. For my $_GET / POST / REQUEST I use this simple function to automatically check if the value is set and avoid any undefined index warnings.


//GET
function GV($key,$default=""){
   return (isset($_GET[$key])) ? $_GET[$key] : $default;
}

I did a quick write up about using this function here: quick php get post request isset function

By: John

John — Mon, 22 Nov 2010 07:09:52 +0000

Thanks for pointing that out. I was more interested in describing the differences between the two functions rather than trying to provide "best practice" approach to using them. But you are right, my code will cause a notice to be displayed, and I will amend it to reflect your suggestions.

By: Ole

Ole — Mon, 22 Nov 2010 06:59:53 +0000

forgot to mention this approach


$foo = (isset($_GET['foo'])) ? $_GET['foo'] : '';
if ($foo == '') { … code here … }

By: Ole

Ole — Mon, 22 Nov 2010 06:57:41 +0000

And what happens if $_GET['foo'] is not defined? You will get "Undefined index: foo" error

From my own experience you should always use isset()

i.e: if ((isset($_GET['foo'])) && ($_GET['foo'] == "")) { … your code here … }

By: query string and isset - CodeCall Programming Forum

query string and isset - CodeCall Programming Forum — Wed, 17 Feb 2010 17:20:18 +0000

[...] query string and isset isset vs. empty John Ciacia [...]

By: social_experiment

social_experiment — Tue, 12 Jan 2010 07:24:33 +0000

Good post, i recently [also] discovered that testing with a 0 will return true if empty() is used. The implications are obvious and since then i always check if the string is empty ( $variable == '' ) instead of using if ( empty($variable) )