PHP FILTER_CALLBACK Filter

❮ 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