When to use isset() and when to use empty()

[dennismonsewicz]

I have been trying to better understand error checking but was wondering what are the best practices for using isset() vs empty()?

 

Thanks!

Dennis

[schilly]

hmmm good question. I'd like to see a good answer.

 

From the manual anyways:

 

empty()

 

The following things are considered to be empty:

 

"" (an empty string)

0 (0 as an integer)

"0" (0 as a string)

NULL

FALSE

array() (an empty array)

var $var; (a variable declared, but without a value in a class)

 

Where as isset():

 

any of the above would be considered true except NULL I think or the variable not existing.

 

 

I think it really depends what you are trying to compare.

[Alex]

You use them for just what they sound like they should be used for. isset is used if you want to see that a variable is set, and empty is to see if a variable isn't null. isset should be used when checking for variables that have a possibility to be unset (like when a form is submitted), because it's the only way to test if a variable is set without getting a notice if it isn't.

 

$var = '';
if(isset($var)) // true
{
    // ...
}

if(!empty($var)) // false
{
    // ...
}

[schilly]

form example.

 

for checking for a submit I use isset() but if I want to see if a field is blank, I use empty().

[gwolgamott]

Here's a good list of when, where , why and the why nots of using empty() http://www.zachstronaut.com/posts/2009/02/09/careful-with-php-empty.html

[dennismonsewicz]

Thanks everyone! I will check out that website mentioned