There are various predefine “superglobals” in PHP. These variables can easily accessible in function or class.
Following are the superglobals variables:
- $GLOBALS
- $_SERVER
- $_REQUEST
- $_POST
- $_GETetc.
PHP $GLOBALS
The “
$GLOBAL” isa keyword that is used to accesssuper global variablefrom anywhere in the PHP script.
Example 1:
<?php
$nos1 = 20;
$nos2 = 30;
function addition() {
$GLOBALS['nos'] = $GLOBALS['nos1'] + $GLOBALS['nos2'];
}
addition();
echo $nos;
?>
Output
50
PHP $_SERVER
PHP $_SERVER is a PHP super global variable that holds the information about headers, paths, and script locations.
Example 2:
<?php
echo $_SERVER['PHP_SELF'];
echo "<br>";
echo $_SERVER['SERVER_NAME'];
echo "<br>";
echo $_SERVER['HTTP_HOST'];
echo "<br>";
echo $_SERVER['HTTP_USER_AGENT'];
echo "<br>";
echo $_SERVER['SCRIPT_NAME'];
?>
Output
/crud/hello.php
localhost
localhost
Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36
/crud/hello.php
Superglobals variables are given below:
| Element/Code |
Description |
| $_SERVER['PHP_SELF'] |
Returns the filename of the currently executing script |
| $_SERVER['GATEWAY_INTERFACE'] |
Returns the version of the Common Gateway Interface (CGI) the server is using |
| _SERVER['SERVER_ADDR'] |
Returns the IP address of the host server |
| $_SERVER['HTTPS'] |
Is the script queried through a secure HTTP protocol |
| $_SERVER['SCRIPT_URI'] |
Returns the URI of the current page |
PHP $_REQUEST
PHP $_REQUEST is used to gather data after submitting html form.
Example:
<html>
<body>
<h3>Enter Your Name to Display result</h3>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
<input type="text" name="fname" placeholder="Enter your name..."><br><br>
<input type="submit">
</form>
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
// collect value of input field
$name = $_REQUEST['fname'];
if (empty($name)) {
echo "Name is empty";
} else {
echo $name;
}
}
?>
</body>
</html>
PHP $_POST
PHP $_POST is used to collect data after submitting the form using
“$_post”method. It is also used to pass the variables.
Example
<html>
<body>
<h3>Enter Your Name to Display result</h3>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
<input type="text" name="fname" placeholder="Enter your name..."><br><br>
<input type="submit">
</form>
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
// collect value of input field
$name = $_POST['fname'];
if (empty($name)) {
echo "Name is empty";
} else {
echo $name;
}
}
?>
</body>
</html>
