A better alternative to print_r / var_dump
PHP CSS JavaScript


REF, or r() is a nicer alternative to PHP's print_r / var_dump functions.



  • (server) PHP 5.3+ (5.4+ displays additional info)
  • (client) Any browser, except IE 8 and lower of course

Installation using Composer

Add REF to your composer.json:

    "require": {
        "digitalnature/php-ref": "dev-master"

Now tell composer to download the bundle by running:

$ php composer.phar update digitalnature/php-ref

Composer will install the bundle to the directory vendor/digitalnature.


Basic example:

// include the class (not needed if project runs with Composer because it's auto-loaded)
require '/full/path/to/ref.php';

// display info about defined classes

// display info about global variables

To print in text mode you can use the rt() function instead:


To terminate the script after the info is dumped, prepend the bitwise NOT operator:

~r($var);   // html
~rt($var);  // text

Prepending the error control operator (@) will return the information:

$output = @r($var);   // html
$output = @rt($var);  // text

Keyboard shortcuts (javascript must be enabled):

  • X - collapses / expands all levels
  • Ctrl + X - toggles display state

To modify the global configuration call ref::config():

// example: initially expand first 3 levels
ref::config('expLvl', 3);

You can also add configuration options in your php.ini file like this:

ref.expLvl = 3
ref.maxDepth = 4

Currently available options and their default values:

Option Default Description
'expLvl' 1 Initially expanded levels (for HTML mode only). A negative value will expand all levels
'maxDepth' 6 Maximum depth (0 to disable); note that disabling it or setting a high value can produce a 100+ MB page when input involves large data
'showIteratorContents' FALSE Display iterator data (keys and values)
'showResourceInfo' TRUE Display additional information about resources
'showMethods' TRUE Display methods and parameter information on objects
'showPrivateMembers' FALSE Include private properties and methods
'showStringMatches' TRUE Perform and display string matches for dates, files, json strings, serialized data, regex patterns etc. (SLOW)
'formatters' array() Custom/external formatters (as associative array: format => className)
'shortcutFunc' array('r', 'rt') Shortcut functions used to detect the input expression. If they are namespaced, the namespace must be present as well (methods are not supported)
'stylePath' '{:dir}/ref.css' Local path to a custom stylesheet (HTML only); FALSE means that no CSS is included.
'scriptPath' '{:dir}/ref.js' Local path to a custom javascript (HTML only); FALSE means no javascript (tooltips / toggle / kbd shortcuts require JS)
'showUrls' FALSE Gets information about URLs. Setting to false can improve performance (requires showStringMatches to be TRUE)
'timeout' 10 Stop execution after this amount of seconds, forcing an incomplete listing. Applies to all calls
'validHtml' FALSE For HTML mode only. Whether to produce W3C-valid HTML (larger code output) or unintelligible, potentially browser-incompatible but much smaller code output

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