# Double not (!!) operator in PHP

In the Double not operator (!!), the first not i.e. ! is used to negate a value, whereas the second not i.e.! again negates. To implement Double not operator in PHP, the code is as follows−

## Example

Live Demo

<?php
$str = "0.1"; echo "Value =$str";
$res = !!$str;
echo "Double Negated Value = $res"; ?> ## Output This will produce the following output− Value = 0.1 Double Negated Value = 1 ## Example Let us now see another example − Live Demo <?php$str = "100.56";
echo "String = $str";$num = floatval($str); echo "Number (Converted from String) =$num";
$res = !!$num;
echo "Double Negated Value = \$res";
?>

## Output

This will produce the following output−

String = 100.56
Number (Converted from String) = 100.56
Double Negated Value = 1