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PHP Global variables / Superglobal variables

  • Hello guys ! In today's tutorial we will learn about PHP superglobal variables.
  • PHP superglobal variables are built in variables in PHP .There are many Global variables in PHP like ...
  • $_REQUEST
  • $_COOKIE
  • $_SESSION
  • $_GET
  • $_POST
  • $_SERVER
  • $GLOBALS
  • Multiple lines comment

$GLOBALS :

  • This global variable in PHP is used for making any variable global .

PHP Example

Edit it yourself 

<!DOCTYPE html>
<html>
<body>

<?php
  $x = 10;
  $y = 10;
  function sum()
  {
     $GLOBALS['z'] = $GLOBALS['x']+$GLOBALS['y'];
  }
  sum();
  echo $z;
?>


</body>
</html>

Output :

Edit it yourself

20


$_SERVER :

  • $_SERVER is a variable that stores data like path , header and script locations etc , or we can say it provides information about server and it's execution enervironment .
  • The values in the `$_SERVER` array are generated by the web server and are accessible within PHP scripts.
  • - `$_SERVER['PHP_SELF']`: The filename of the currently executing script, relative to the document root.
  • - `$_SERVER['SERVER_NAME']`: The name of the server host where the script is running.
  • - `$_SERVER['REQUEST_METHOD']`: The HTTP request method used to access the script (e.g., "GET", "POST", "PUT").
  • - `$_SERVER['QUERY_STRING']`: The query string portion of the URL, if any.
  • - `$_SERVER['HTTP_USER_AGENT']`: The user agent string of the client's browser.
  • - `$_SERVER['REMOTE_ADDR']`: The IP address of the client making the request.

PHP Example

Edit it yourself 

<!DOCTYPE html>
<html>
<body>

<?php
  echo $_SERVER['PHP_SELF'];
  echo "<br>";
  echo $_SERVER['SERVER_NAME'];
  echo "<br>";
  echo $_SERVER['HTTP_HOST'];
  echo "<br>";
  echo $_SERVER['HTTP_REFERER'];
  echo "<br>";
  echo $_SERVER['HTTP_USER_AGENT'];
  echo "<br>";
  echo $_SERVER['SCRIPT_NAME'];
?>


</body>
</html>

Output :

Edit it yourself
  • /wts/day7.php
  • localhost
  • localhost
  • http://localhost/wts/day7.php
  • Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 Safari/537.36 /wts/day7.php

    • $_REQUEST :

    • $_REQUEST in PHP is used for collecting data that is submitted by the user by get or post method ..
    • In form when method is declared as GET or POST so when the data is submitted that data called in php by using $_REQUEST method ...

    PHP Example

    Edit it yourself 
    
<!DOCTYPE html>
<html lang="en">
<head>
   <meta charset="UTF-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title></title>
</head>
<body>
   <form method="get">
     <table>
      <tr>
         <th>Username</th>
         <td>
            <input type="text" name="unm" placeholder="Enter username"/>
         </td>
      </tr>
      <tr>
         <th>Password</th>
        <td>
          <input type="password" name="pass" placeholder="enter password">
        </td>
      </tr>
      <tr>
         <th colspan="2">
           <input type="submit" name="submit">
         </th>
      </tr>
     </table>
   </form>
</body>
</html>

<?php 
   
if(isset($_REQUEST['submit']))
{
   $unm=$_REQUEST['unm'];
   $pass=$_REQUEST['pass'];
   
   echo $unm."<br>".$pass;
}
?>

    Output :

    Edit it yourself
    hello

    $_POST : :

    • $_POST is a superglobal variable it is used to pass data when you click submit in any form .
    • In post method there's no limit of passing data . Post method is safe for passsing data like passwords or any personal informations or any kind of private data .

    PHP Example

    Edit it yourself 
    

<!DOCTYPE html>
<html lang="en">
<head>
   <meta charset="UTF-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>POST</title>
</head>
<body>
   <form method="post">
      <input type="text" name="name" placeholder="Enter name :"/>
      <input type="submit" name="submit">
   </form>
   <?php 
        if(isset($_REQUEST['submit']))
        {
         $nm = $_POST['name'];
         echo $nm; 
        }
   ?>
</body>
</html>

<?php 
   
if(isset($_REQUEST['submit']))
{
   $unm=$_REQUEST['unm'];
   $pass=$_REQUEST['pass'];
   
   echo $unm."<br>".$pass;
}
?>

    Output :

    Edit it yourself
    hello