Question

which is better?

if (!empty($val)) { // do something }

and

if ($val) { // do something }

when i test it with PHP 5, all cases produce the same results. what about PHP 4, or have any idea which way is better?

Answer 1

You should use the empty() construct when you are not sure if the variable even exists. If the variable is expected to be set, use if ($var) instead.

empty() is the equivalent of !isset($var) || $var == false. It returns true if the variable is:

• "" (an empty string)
• 0 (0 as an integer)
• 0.0 (0 as a float)
• "0" (0 as a string)
• NULL
• FALSE
• array() (an empty array)
• var $var; (a variable declared, but without a value in a class)