< Complete PHP Filter Reference
Definition and Usage
The FILTER_CALLBACK filter calls a user defined function to filter the value.
This filter gives us full control over the data filtering
The specified functions must be in an associative array with the name "options". See example below
- Name: "callback"
- ID-number: 1024
Tips and Notes
Tip: You can create your own user defined function or use an existing PHP function
Example 1
Using a user defined function:
<?php
function convertSpace($string)
{
return str_replace(" ", "_", $string);
}
$string = "Peter is a great guy!";
echo filter_var($string, FILTER_CALLBACK,
array("options"=>"convertSpace"));
?>
The output of the code will be:
Peter_is_a_great_guy!
Example 2
Using an existing PHP function
<?php
$string="Peter is a great guy!";
echo filter_var($string, FILTER_CALLBACK,
array("options"=>"strtoupper"));
?>
The output of the code will be:
PETER IS A GREAT GUY!
< Complete PHP Filter Reference