PHP empty() Function

Example

Check whether a variable is empty. Also check whether the variable is set/declared:

<?php
$a = 0;

// True because $a is empty
if (empty($a)) {
echo "Variable 'a' is empty.<br>";
}

// True because $a is set
if (isset($a)) {
echo "Variable 'a' is set";
}
?>

Try it Yourself »

Definition and Usage

The empty() function checks whether a variable is empty or not.

This function returns false if the variable exists and is not empty, otherwise it returns true.

The following values evaluates to empty:

0
0.0
"0"
""
NULL
FALSE
array()

Syntax

empty(variable);

Parameter Values

Parameter	Description
variable	Required. Specifies the variable to check

Technical Details

Return Value:	FALSE if variable exists and is not empty, TRUE otherwise
Return Type:	Boolean
PHP Version:	4.0+
PHP Changelog:	PHP 5.5: Support for expressions, not only variables PHP 5.4: Non-numeric offsets of strings returns TRUE

❮ PHP Variable Handling Reference