(PHP 5 >= 5.2.0)
filter_var — Filters a variable with a specified filter
Value to filter.
ID of a filter to use. Defaults to FILTER_DEFAULT.
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, callback 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 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
$var = filter_var('oops', FILTER_VALIDATE_BOOLEAN,
array('flags' => FILTER_NULL_ON_FAILURE));
// callback filter
function foo($value)
{
$ret = new stdClass;
$ret->value = filter_var($value, FILTER_VALIDATE_BOOLEAN,
array('flags' => FILTER_NULL_ON_FAILURE));
return $ret;
}
$var = filter_var('yes', FILTER_CALLBACK, array('options' => 'foo'));
?>
Returns the filtered data, or FALSE if the filter fails.
Example #1 A filter_var() example
<?php
var_dump(filter_var('bob@example.com', FILTER_VALIDATE_EMAIL));
var_dump(filter_var('example.com', FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED));
?>
上例将输出：
string(15) "bob@example.com" bool(false)