php: '0' as a string with empty()

Question

I want a 0 to be considered as an integer and a \'0\' to be considered as a string but empty() considers the \'0\' as a string in the example below,

$var = \         


        

Answer 1

empty is by far the most confusing and useless function in the php repertoire. Don't use it.

There are three separate things you want to know when checking a value.

• the value exists (use isset)
• the value has a specific type (use is_xxx)
• the value has specific properties (use comparison operators, strpos or regular expressions).

(the last two can be combined into one with typecasts or '===').

Examples:

if(isset($var) && is_string($var) && strlen($var) > 0)...
if(isset($var) && intval($var) > 0)...
if(isset($var) && $var === '0')...

This seems more verbose, but shows clearly what you're doing. For structural objects it often makes sense to have a shortcut getter, e.g.

 /// get a string
 function s($ary, $key, $default = '') {
     if(!isset($ary[$key])) return $default;
     $s = trim($ary[$key]);
     return strlen($s) ? $s : $default;
 }
 /// get a natural number
 function n($ary, $key, $default = 0) {
     $n = intval(s($ary, $key));
     return $n > 0 ? $n : $default;
 }

 $name = s($_POST, 'name');
 $age  = n($_POST, 'age');