filter_var
(PHP 5 >= 5.2.0, PHP 7, PHP 8)
filter_var — Filters a variable with a specified filter
Parameters
-
value -
Value to filter. Note that scalar values are converted to string internally before they are filtered.
-
filter -
The ID of the filter to apply. The Types of filters manual page lists the available filters.
If omitted,
FILTER_DEFAULTwill be used, which is equivalent toFILTER_UNSAFE_RAW. This will result in no filtering taking place by default. -
options -
Associative array of options or bitwise disjunction of flags. If filter accepts options, flags can be provided in "flags" field of array. For the "callback" filter, callable type should be passed. The callback must accept one argument, the value to be filtered, and return the value after filtering/sanitizing it.
<?php
// for filters that accept options, use this format
$options = array(
'options' => array(
'default' => 3, // value to return if the filter fails
// other options here
'min_range' => 0
),
'flags' => FILTER_FLAG_ALLOW_OCTAL,
);
$var = filter_var('0755', FILTER_VALIDATE_INT, $options);
// for filters that only accept flags, you can pass them directly
$var = filter_var('oops', FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
// for filters that only accept flags, you can also pass as an array
$var = filter_var('oops', FILTER_VALIDATE_BOOLEAN,
array('flags' => FILTER_NULL_ON_FAILURE));
// callback validate filter
function foo($value)
{
// Expected format: Surname, GivenNames
if (strpos($value, ", ") === false) return false;
list($surname, $givennames) = explode(", ", $value, 2);
$empty = (empty($surname) || empty($givennames));
$notstrings = (!is_string($surname) || !is_string($givennames));
if ($empty || $notstrings) {
return false;
} else {
return $value;
}
}
$var = filter_var('Doe, Jane Sue', FILTER_CALLBACK, array('options' => 'foo'));
?>
Return Values
Returns the filtered data, or false if the filter fails.
Examples
Example #1 A filter_var() example
<?php
var_dump(filter_var('bob@example.com', FILTER_VALIDATE_EMAIL));
var_dump(filter_var('http://example.com', FILTER_VALIDATE_URL, FILTER_FLAG_PATH_REQUIRED));
?>
The above example will output:
string(15) "bob@example.com" bool(false)
See Also
- filter_var_array() - Gets multiple variables and optionally filters them
- filter_input() - Gets a specific external variable by name and optionally filters it
- filter_input_array() - Gets external variables and optionally filters them
- Types of filters
