filter_var
(PHP 5 >= 5.2.0, PHP 7)
filter_var — 使用特定的过滤器过滤一个变量
参数
-
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。
-
filter
-
The 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 toFILTER_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'));
?>
返回值
Returns the filtered data, or FALSE
if the filter fails.
范例
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)
参见
- filter_var_array() - 获取多个变量并且过滤它们
- filter_input() - 通过名称获取特定的外部变量,并且可以通过过滤器处理它
- filter_input_array() - 获取一系列外部变量,并且可以通过过滤器处理它们
- Types of filters
- callback 类型的信息