PHP Basic
PHP HOME PHP Intro PHP Install PHP Syntax PHP Variables PHP String PHP Operators PHP If...Else PHP Switch PHP Arrays PHP Sorting Arrays PHP While Loops PHP For Loops PHP Functions PHP Forms PHP $_GET PHP $_POSTPHP Advanced
PHP Arrays Multi PHP Date PHP Include PHP File PHP File Upload PHP Cookies PHP Sessions PHP E-mail PHP Secure E-mail PHP Error PHP Exception PHP FilterPHP Database
PHP MySQL Intro PHP MySQL Connect PHP CREATE DB/Table PHP INSERT INTO PHP SELECT PHP WHERE PHP ORDER BY PHP UPDATE PHP DELETE PHP ODBCPHP XML
XML Expat Parser XML DOM XML SimpleXMLPHP and AJAX
AJAX Intro AJAX PHP AJAX Database AJAX XML AJAX Live Search AJAX RSS Reader AJAX PollPHP Reference
PHP Array PHP Calendar PHP Date PHP Directory PHP Error PHP Filesystem PHP Filter PHP FTP PHP HTTP PHP Libxml PHP Mail PHP Math PHP Misc PHP MySQLi PHP SimpleXML PHP String PHP XML PHP Zip PHP TimezonesPHP Quiz
PHP Quiz PHP CertificatePHP FILTER_CALLBACK Filter
Complete PHP Filter Reference
Definition and Usage
The FILTER_CALLBACK filter calls a user defined function to filter the value.
This filter gives us full control over the data filtering
The specified functions must be in an associative array with the name "options". See example below
- Name: "callback"
- ID-number: 1024
Tips and Notes
Tip: You can create your own user defined function or use an existing PHP function
Example 1
Using a user defined function:
<?php
function convertSpace($string)
{
return str_replace(" ", "_", $string);
}
$string = "Peter is a great guy!";
echo filter_var($string, FILTER_CALLBACK,
array("options"=>"convertSpace"));
?>
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"));
?>
$string="Peter is a great guy!";
echo filter_var($string, FILTER_CALLBACK,
array("options"=>"strtoupper"));
?>
The output of the code will be:
PETER IS A GREAT GUY!
Complete PHP Filter Reference
W3Schools' Online Certification
The perfect solution for professionals who need to balance work, family, and career building.
More than 10 000 certificates already issued!
The HTML Certificate documents your knowledge of HTML.
The HTML5 Certificate documents your knowledge of advanced HTML5.
The CSS Certificate documents your knowledge of advanced CSS.
The JavaScript Certificate documents your knowledge of JavaScript and HTML DOM.
The jQuery Certificate documents your knowledge of jQuery.
The XML Certificate documents your knowledge of XML, XML DOM and XSLT.
The ASP Certificate documents your knowledge of ASP, SQL, and ADO.
The PHP Certificate documents your knowledge of PHP and SQL (MySQL).
Your suggestion:
Close [X]
Thank You For Helping Us!
Your message has been sent to W3Schools.
Close [X]
