(PHP 5 >= 5.2.0, PHP 7)
filter_var — 使用特定的过滤器过滤一个变量
variable待过滤的变量。注意：标量的值在过滤前，会被转换成字符串。
filterThe ID of the filter to apply. The Types of filters manual page lists the available filters.
If omitted, FILTER_DEFAULT will be used, which is
equivalent to
FILTER_UNSAFE_RAW.
This will result in no filtering taking place by default.
options一个选项的关联数组，或者按位区分的标示。如果过滤器接受选项，可以通过数组的 "flags" 位去提供这些标示。 对于回调型的过滤器，应该传入 callable。这个回调函数必须接受一个参数，即待过滤的值，并且 返回一个在过滤/净化后的值。
<?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 filter that only accept flags, you can pass them directly
$var = filter_var('oops', FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
// for filter 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'));
?>
Returns the filtered data, or FALSE if the filter fails.
Example #1 一个 filter_var() 的例子
<?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));
?>
以上例程会输出：
string(15) "bob@example.com" bool(false)