I have to use the empty () php function

Question

what's better?

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

and

 if ($val) { // do something } 

when I test it with PHP 5, all cases give 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 this variable exists. If you expect the variable to be set, use if ($var) instead.

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

• "" (empty string)
• 0 (0 as an integer)
• 0.0 (0 as a float)
• "0" (0 as a string)
• NULL
• FALSE
• array() (empty array)
• var $var; (declared variable, but no value in the class)

Answer 2

Read the manual:

empty () is the opposite of (boolean) var, except that a warning is not generated when the variable is not set.