isset or !empty for $_GET[var]

Question

i recently had to do a "test" for a job, and i got feed back saying that this statement was incorrect:

$images = $flickr->get_images(5, !empty($_GET['pg']) ? $_GET['pg'] : 1);

The "supposed" error was generated via the ternary operator on the first time the page was loaded, as there was no "?pg=1" (or whatever) passed via the query string.

The feed back said i should have used isset instead. I have looked at various posts both here (question 1960509) and blogs, but cannot find any definitive answer.

Is this really an error? How can i replicate this issue? do i need to put on E_STRICT or something in my php.ini file? Or might this be due to an older version of php?

Note: please don't tell me about how i should validate things.. i know this... it was a test to just see if i could use the flickr api calls.

Answer 1

This is perfectly fine. empty is not an actual function, it's a language construct. It does not issue a warning if a variable is not set (in that case the variable is considered empty, thus the 'function' returns TRUE just as you want), and additionally it checks for empty or zero values.

You could see empty as a normal isset check with an additional loose comparison to FALSE:

empty($var) === (!isset($var) || $var == FALSE)