PHP Global Variables - Superglobals Example

PHP 8 , PHP

Nicesnippets

384

26-07-2021


PHP Global Variables - Superglobals Example

Hi guys,

Today i will explained how to use php Global Variables and Superglobals. This example is so easy to use in php.

Superglobals were introduced in PHP 4.1.0, and are built-in variables that are always available in all scopes.

Some predefined variables in PHP are "superglobals", which means that they are always accessible, regardless of scope - and you can access them from any function, class or file without having to do anything special.

So let's start to the example.

The PHP superglobal variables are:

$GLOBALS


$_SERVER

$_REQUEST

$_POST

$_GET

$_FILES

$_ENV

$_COOKIE

$_SESSION

$GLOBALS

$GLOBALS is a PHP super global variable which is used to access global variables from anywhere in the PHP script.

<!DOCTYPE html>

<html>

<body>

<?php

$x = 75;

$y = 25;

function addition() {

$GLOBALS['z'] = $GLOBALS['x'] + $GLOBALS['y'];

}

addition();

echo $z;

?>

</body>

</html>

Output

100

$_SERVER

$_SERVER is a PHP super global variable which holds information about headers, paths, and script locations.

<!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

/demo/demo_global_server.php

35.194.26.41

35.194.26.41

https://tryphp.w3schools.com/showphp.php?filename=demo_global_server

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:90.0) Gecko/20100101 Firefox/90.0

/demo/demo_global_server.php

$_REQUEST

PHP $_REQUEST is a PHP super global variable which is used to collect data after submitting an HTML form.

<!DOCTYPE html>

<html>

<body>

<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">

Name: <input type="text" name="fname">

<input type="submit">

</form>

<?php

if ($_SERVER["REQUEST_METHOD"] == "POST") {

// collect value of input field

$name = $_REQUEST['fname'];

if (empty($name)) {

echo "Name is empty";

} else {

echo $name;

}

}

?>

</body>

</html>

Output

abc

$_POST

PHP $_POST is a PHP super global variable which is used to collect form data after submitting an HTML form with method="post". $_POST is also widely used to pass variables.

<!DOCTYPE html>

<html>

<body>

<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">

Name: <input type="text" name="fname">

<input type="submit">

</form>

<?php

if ($_SERVER["REQUEST_METHOD"] == "POST") {

// collect value of input field

$name = $_REQUEST['fname'];

if (empty($name)) {

echo "Name is empty";

} else {

echo $name;

}

}

?>

</body>

</html>

Output

abc

$_GET

PHP $_GET is a PHP super global variable which is used to collect form data after submitting an HTML form with method="get".

$_GET can also collect data sent in the URL.

<!DOCTYPE html>

<html>

<body>

<a href="test_get.php?subject=PHP&web=W3schools.com">Click $GET</a>

</body>

</html>

Output

Click $GET

Now you can check your own.

I hope it can help you...


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