get_defined_vars

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

get_defined_vars — Returns an array of all defined variables

Description

array get_defined_vars ( void )

This function returns a multidimensional array containing a list of all defined variables, be them environment, server or user-defined variables, within the scope that get_defined_vars() is called.

Return Values

A multidimensional array with all the variables.

Examples

Example #1 get_defined_vars() Example


<?php
$b = array(1, 1, 2, 3, 5, 8);

$arr = get_defined_vars();

// print $b
print_r($arr["b"]);

/* print path to the PHP interpreter (if used as a CGI)
 * e.g. /usr/local/bin/php */
echo $arr["_"];

// print the command-line parameters if any
print_r($arr["argv"]);

// print all the server vars
print_r($arr["_SERVER"]);

// print all the available keys for the arrays of variables
print_r(array_keys(get_defined_vars()));
?>

User Contributed Notes

zabmilenko at hotmail dot com

9 years ago


A little gotcha to watch out for:

If you turn off RegisterGlobals and related, then use get_defined_vars(), you may see something like the following:

<?php
Array
(
    [GLOBALS] => Array
        (
            [GLOBALS] => Array
 *RECURSION*
            [_POST] => Array()
            [_GET] => Array()
            [_COOKIE] => Array()
            [_FILES] => Array()
        )

    [_POST] => Array()
    [_GET] => Array()
    [_COOKIE] => Array()
    [_FILES] => Array()

)
?>

Notice that $_SERVER isn't there.  It seems that php only loads the superglobal $_SERVER if it is used somewhere.  You could do this:

<?php
print '<pre>' . htmlspecialchars(print_r(get_defined_vars(), true)) . '</pre>';
print '<pre>' . htmlspecialchars(print_r($_SERVER, true)) . '</pre>';
?>

And then $_SERVER will appear in both lists.  I guess it's not really a gotcha, because nothing bad will happen either way, but it's an interesting curiosity nonetheless.

jgettys at gnuvox dot com

14 years ago


Simple routine to convert a get_defined_vars object to XML.



<?php

function obj2xml($v, $indent='') {

  while (list($key, $val) = each($v)) {

    if ($key == '__attr') continue;

    // Check for __attr

    if (is_object($val->__attr)) {

      while (list($key2, $val2) = each($val->__attr)) {

        $attr .= " $key2=\"$val2\"";

      }

    }

    else $attr = '';

    if (is_array($val) || is_object($val)) {

      print("$indent<$key$attr>\n");

      obj2xml($val, $indent.'  ');

      print("$indent</$key>\n");

    }

    else print("$indent<$key$attr>$val</$key>\n");

  }

}



//Example object

$x->name->first = "John";

$x->name->last = "Smith";

$x->arr['Fruit'] = 'Bannana';

$x->arr['Veg'] = 'Carrot';

$y->customer = $x;

$y->customer->__attr->id='176C4';



$z = get_defined_vars();

obj2xml($z['y']);

?>



will output:

<customer id="176C4">

  <name>

    <first>John</first>

    <last>Smith</last>

  </name>

  <arr>

    <Fruit>Bannana</Fruit>

    <Veg>Carrot</Veg>

  </arr>

</customer>

donovan at example dot com

7 years ago


As a note, get_defined_vars() does not return a set of variable references (as I hoped). For example:

<?php

// define a variable
$my_var = "foo";

// get our list of defined variables
$defined_vars = get_defined_vars();

// now try to change the value through the returned array
$defined_vars["my_var"] = "bar";

echo $my_var, "\n";

?>

will output "foo" (the original value). It'd be nice if get_defined_vars() had an optional argument to make them references, but I imagine its a rather specialized request. You can do it yourself (less conveniently) with something like:

<?php

$defined_vars = array();
$var_names = array_keys(get_defined_vars());

foreach ($var_names as $var_name)
{
    $defined_vars[$var_name] =& $$var_name;
}

?>

ryanlwh at yahoo dot com

3 years ago


Since get_defined_vars() only gets the variables at the point you call the function, there is a simple way to get the variables defined within the current scope.

<?php
// The very top of your php script
$vars = get_defined_vars();

// Now do your stuff
$foo = 'foo';
$bar = 'bar';

// Get all the variables defined in current scope
$vars = array_diff(get_defined_vars(),$vars);

echo '<pre>';
print_r($vars);
echo '</pre>';
?>

SyCo

7 years ago


Here's a very simple function for debugging. It's far from perfect but I find it very handy. It outputs the var value and the var name on a new line. The problem is it'll echo any vars and their name if they share the same value. No big deal when debugging and saves the hassle of writing the HTML and var name when echoing a variable. (ev=echo variable). Using get_defined_vars() inside a function renames the var name to the functions variable so isn't as useful for debugging. Of course, you'll need access to the $GLOBALS array
<?
function ev($variable){
    foreach($GLOBALS as $key => $value){
        if($variable===$value){
            echo '<p>'.$key.' - '.$value.'</p>';
        }
    }
}

$a=0;
ev($a);
$b=0;
ev($b);
$c=0;
ev($c);
?>
Will output
a - 0

a - 0
b - 0

a - 0
b - 0
c - 0

lbowerh at adelphia dot net

11 years ago


Here is a function which generates a debug report for display or email
using get_defined_vars. Great for getting a detailed snapshot without
relying on user input.

<?php
function generateDebugReport($method,$defined_vars,$email="undefined"){
    // Function to create a debug report to display or email.
    // Usage: generateDebugReport(method,get_defined_vars(),email[optional]);
    // Where method is "browser" or "email".

    // Create an ignore list for keys returned by 'get_defined_vars'.
    // For example, HTTP_POST_VARS, HTTP_GET_VARS and others are 
    // redundant (same as _POST, _GET)
    // Also include vars you want ignored for security reasons - i.e. PHPSESSID.
    $ignorelist=array("HTTP_POST_VARS","HTTP_GET_VARS",
    "HTTP_COOKIE_VARS","HTTP_SERVER_VARS",
    "HTTP_ENV_VARS","HTTP_SESSION_VARS",
    "_ENV","PHPSESSID","SESS_DBUSER",
    "SESS_DBPASS","HTTP_COOKIE");

    $timestamp=date("m/d/y h:m:s");
    $message="Debug report created $timestamp\n";

    // Get the last SQL error for good measure, where $link is the resource identifier
    // for mysql_connect. Comment out or modify for your database or abstraction setup.
    global $link;
    $sql_error=mysql_error($link);
    if($sql_error){
      $message.="\nMysql Messages:\n".mysql_error($link);
    }
    // End MySQL

    // Could use a recursive function here. You get the idea ;-)
    foreach($defined_vars as $key=>$val){
      if(is_array($val) && !in_array($key,$ignorelist) && count($val) > 0){
        $message.="\n$key array (key=value):\n";
        foreach($val as $subkey=>$subval){
          if(!in_array($subkey,$ignorelist) && !is_array($subval)){
            $message.=$subkey." = ".$subval."\n";
          }
          elseif(!in_array($subkey,$ignorelist) && is_array($subval)){
            foreach($subval as $subsubkey=>$subsubval){
              if(!in_array($subsubkey,$ignorelist)){
                $message.=$subsubkey." = ".$subsubval."\n";
              }
            }
          }
        }
      }
      elseif(!is_array($val) && !in_array($key,$ignorelist) && $val){
        $message.="\nVariable ".$key." = ".$val."\n";
      }
    }

    if($method=="browser"){
      echo nl2br($message);
    }
    elseif($method=="email"){
      if($email=="undefined"){
        $email=$_SERVER["SERVER_ADMIN"];
      }

      $mresult=mail($email,"Debug Report for ".$_ENV["HOSTNAME"]."",$message);
      if($mresult==1){
        echo "Debug Report sent successfully.\n";
      }
      else{
        echo "Failed to send Debug Report.\n";      
      }
    }
}
?>

mail at mkharitonov dot net

1 year ago


Reference variables are returned by reference (tested on PHP 5.5.11):
<?php
$a = null;
$b = &$a;
get_defined_vars()['b'] = 4;
var_dump($b); // int(4)
?>

sergeyzuzic at mail dot ru

5 months ago


dirty code sample:

print_r(compact(array_keys(get_defined_vars())));

Anonymous

5 years ago


get_defined_vars() returns ALL the vars (in the current scope), what if you just want all YOUR vars, not PHP's super-globals?



<?php

    var_export(array_diff(get_defined_vars(), array(array())));

?>



Example...



<?php

    $TOP_LEVEL_VAR=1;

    var_export(array_diff(get_defined_vars(), array(array())));

?>



The output (with register_globals off) should be...



array (

  'TOP_LEVEL_VAR' => 1,

)



...it perfectly eliminated all the super-globals, without me having to specify them! (note with register_globals on, the output includes those globals, then TOP_LEVEL_VAR).



Here it is, as a function...(it's the best I could do {I can't call get_defined_vars() inside get_user_defined_vars() cuz of the scope issue}).



<?php

    header('Content-type: text/plain');



    $TOP_LEVEL_VAR=1;



    echo 'register_globals(';

    echo ini_get('register_globals');

    echo ') '.phpversion()."\n";



    var_export(get_user_defined_vars(get_defined_vars()));



    function get_user_defined_vars($vars) {

        return array_diff($vars, array(array()));

    }

?>



Note that originally I had an array of the super-globals I wanted removed from get_defined_vars()'s array, then I noticed even an empty double-array, array(array()), made it give me the correct result. Weird.



This was tested on PHP 5.2.9.

Johan de Vries

5 years ago


Note that this only returns things you've used. See http://bugs.php.net/bug.php?id=52110 . So don't expect this to have the $this entry, unless you assign $this to return $this.

meint at meint dot net

5 years ago


Please be aware that function_get_vars only returns the variables defined at the point before you call the function_get_vars function, it does not scan the entire function for you, only the lines before you call it.

get_defined_vars

Description

Return Values

Examples

See Also

User Contributed Notes