PHP: Hypertext Preprocessor

Tip

As with anything that outputs its result directly to the browser, the output-control functions can be used to capture the output of this function, and save it in a string (for example).

Example #1 var_dump() example

The above example will output:

array(3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  array(3) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
    [2]=>
    string(1) "c"
  }
}

The above example will output:

Keep in mind if you have xdebug installed it will limit the var_dump() output of array elements and object properties to 3 levels deep.

To change the default, edit your xdebug.ini file and add the folllowing line:
xdebug.var_display_max_depth=n

More information here:
http://www.xdebug.org/docs/display

If you're like me and uses var_dump whenever you're debugging, you might find these two "wrapper" functions helpful.

This one automatically adds the PRE tags around the var_dump output so you get nice formatted arrays.

<?phpfunction var_dump_pre($mixed = null) {
echo '<pre>';
var_dump($mixed);
echo '</pre>';
return null;
}?>

This one returns the value of var_dump instead of outputting it.

<?phpfunction var_dump_ret($mixed = null) {
ob_start();
var_dump($mixed);
$content = ob_get_contents();
ob_end_clean();
return $content;
}?>

Fairly simple functions, but they're infinitely helpful (I use var_dump_pre() almost exclusively now).

I post a new var_dump function with colors and collapse features. It can also adapt to terminal output if you execute it from there. No need to wrap it in a pre tag to get it to work in browsers.

<?php
function dump_debug($input, $collapse=false) {
$recursive = function($data, $level=0) use (&$recursive, $collapse) {
global $argv;$isTerminal = isset($argv);

if (!

var_dump(get_defined_vars());
will dump all defined variables to the browser.

<?php
/**
* Better GI than print_r or var_dump -- but, unlike var_dump, you can only dump one variable.
* Added htmlentities on the var content before echo, so you see what is really there, and not the mark-up.
*
* Also, now the output is encased within a div block that sets the background color, font style, and left-justifies it
* so it is not at the mercy of ambient styles.
*
* Inspired from: PHP.net Contributions
* Stolen from: [highstrike at gmail dot com]
* Modified by: stlawson *AT* JoyfulEarthTech *DOT* com
*
* @param mixed $var -- variable to dump
* @param string $var_name -- name of variable (optional) -- displayed in printout making it easier to sort out what variable is what in a complex output
* @param string $indent -- used by internal recursive call (no known external value)
* @param unknown_type $reference -- used by internal recursive call (no known external value)
*/
function do_dump(&$var, $var_name = NULL, $indent = NULL, $reference = NULL)
{
$do_dump_indent = "<span style='color:#666666;'>|</span> &nbsp;&nbsp; ";
$reference = $reference.$var_name;
$keyvar = 'the_do_dump_recursion_protection_scheme'; $keyname = 'referenced_object_name';// So this is always visible and always left justified and readable
echo "<div style='text-align:left; background-color:white; font: 100% monospace; color:black;'>";

if (

As Bryan said, it is possible to capture var_dump() output to a string. But it's not quite exact if the dumped variable contains HTML code.

You can use this instead:

<?php
echo '<pre>'; // This is for correct handling of newlines
ob_start();
var_dump($var);
$a=ob_get_contents();
ob_end_clean();
echo htmlspecialchars($a,ENT_QUOTES); // Escape every HTML special chars (especially > and < )
echo '</pre>';
?>

made 2 nifty functions based of what some people contributed here. Hope you find them usefull

usage ... call for the dump function. EG: dump($array, "Array dump");

<?php
////////////////////////////////////////////////////////
// Function: dump
// Inspired from: PHP.net Contributions
// Description: Helps with php debuggingfunction dump(&$var, $info = FALSE)
{
$scope = false;
$prefix = 'unique';
$suffix = 'value';

if(

Be careful this outputs to stdout stream (1) instead of the proper stderr stream (2).

Howdy!

I am working on a pretty large project where I needed to dump a human readable form of whatever into the log files... and I thought var_export was too difficult to read. BigueNique at yahoo dot ca has a nice solution, although I needed to NOT modify whatever was being passed to dump.

So borrowing heavily from BigueNique's (just reworked his function) and someone's idea over in the object cloning page, I came up with the following function.

It makes a complete copy of whatever object you initially pass it, including all recursive definitions and outside objects references, then does the same thing as BigueNique's function. I also heavily reworked what it output, to suit my needs.

<?phpfunction var_log(&$varInput, $var_name='', $reference='', $method = '=', $sub = false) {

static

If you want to save exactly the content of an array into a variable to save ir later for example, use this:

<?php $xml = var_export($xml, true); ?>

You'll have in your same variable the content readable, instead of written down or anything else

I wrote this dandy little function for using var_dump() on HTML documents so I don't have to view the source.

<?php
function htmldump($variable, $height="9em") {
echo "<pre style=\"border: 1px solid #000; height: {$height}; overflow: auto; margin: 0.5em;\">";
var_dump($variable);
echo "</pre>\n";
}
?>

You can pass arguments like this:
<?php
$sql = mysql_query("SELECT id, name, value FROM table WHERE cond = 'value'");
$s = mysql_fetch_assoc($sql);// Dump variable containing the result of the MySQL query
var_dump($s);
?>

The second parameter lets you specify the height of the box. Default is 9em, but if you're expecting a huge output you'll probably want a higher value.

<?php
var_dump($s, "17em");
?>

Happy var_dumping.

You can also use the PEAR package available at http://pear.php.net/package/Var_Dump

which parses the variable content in a very pleasant manner, a lot more easier to "follow" than the built-in var_dump() function.

Of course there are many others, but I prefer this one, because it's simply to use.

Just add at the begining of your file:

<?phprequire('Var_Dump.php'); // make sure the pear package path is set in php.ini
Var_Dump::displayInit(array('display_mode' => 'HTML4_Text'), array('mode' => 'normal','offset' => 4));
?>

then, instead of simply using var_dump($foo), use:

<?php

Var_Dump

It's important to note that the output depends on the precision directive.
<?php
var_dump(10000000000000.5); // float(10000000000000)
ini_set('precision',-1);
var_dump(10000000000000.5); // float(10000000000000.5)
?>

a html-encoded var_dump

<?php
function htmlvardump(){ob_start(); $var = func_get_args(); call_user_func_array('var_dump', $var); echo htmentities(ob_get_clean());}
?>

(creds: ekneuss / mOo @ irc.freenode.net/#php )

dumping objects that reference each other could lead to infinite recursion
<?php
$brother = new Sibling();
$sister = new Sibling();
$brother->sister = $sister;
$sister->brother = $brother;var_dump($brother);
/* dumps all of $brother's properties, including "sister", which dumps all of $sister's properties, including "brother", etc. */
?>