PHP FILTER_VALIDATE_BOOLEAN Filter

Definition and Usage

The FILTER_VALIDATE_BOOLEAN filter validates value as a boolean option.

Name: "boolean"
ID-number: 258

Possible return values:

Returns TRUE for "1", "true", "on" and "yes"
Returns FALSE for "0", "false", "off" and "no"
Returns NULL on failure if FILTER_NULL_ON_FAILURE is set

Example

<?php
$var1="yes";
$var2="off";

var_dump(filter_var($var1, FILTER_VALIDATE_BOOLEAN));
echo "<br>";
var_dump(filter_var($var2, FILTER_VALIDATE_BOOLEAN));
?>

The output of the code will be:

bool(true)
bool(false)

Example

<?php
$var1="Hello";
$var2=23;

var_dump(filter_var($var1, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE));
echo "<br>";
var_dump(filter_var($var2, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE));
?>

The output of the code will be:

NULL
NULL

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