PHP: what’s an alternative to empty(), where string “0” is not treated as empty?


Possible Duplicate:
Fixing the PHP empty function

In PHP, empty() is a great shortcut because it allows you to check whether a variable is defined AND not empty at the same time.

What would you use when you don't want "0" (as a string) to be considered empty, but you still want false, null, 0 and "" treated as empty?

That is, I'm just wondering if you have your own shortcut for this:

if (isset($myvariable) && $myvariable != "") ;// do something
if (isset($othervar  ) && $othervar   != "") ;// do something
if (isset($anothervar) && $anothervar != "") ;// do something
// and so on, and so on

I don't think I can define a helper function for this, since the variable could be undefined (and therefore couldn't be passed as parameter).

Best Solution

This should do what you want:

function notempty($var) {
    return ($var==="0"||$var);

Edit: I guess tables only work in the preview, not in actual answer submissions. So please refer to the PHP type comparison tables for more info.

notempty("")       : false
notempty(null)     : false
notempty(undefined): false
notempty(array())  : false
notempty(false)    : false
notempty(true)     : true
notempty(1)        : true
notempty(0)        : false
notempty(-1)       : true
notempty("1")      : true
notempty("0")      : true
notempty("php")    : true

Basically, notempty() is the same as !empty() for all values except for "0", for which it returns true.

Edit: If you are using error_reporting(E_ALL), you will not be able to pass an undefined variable to custom functions by value. And as mercator points out, you should always use E_ALL to conform to best practices. This link (comment #11) he provides discusses why you shouldn't use any form of error suppression for performance and maintainability/debugging reasons.

See orlandu63's answer for how to have arguments passed to a custom function by reference.