<?php
/*  Predefined array:
*  Automatic global variable --- Superglobal array
*
* 1. Contains information from WEB Server, client, runtime environment, and user input data
* 2. These arrays are special
* 3. These arrays can be used directly in the global scope
* 4. The user cannot customize these arrays, but the way they are manipulated and the way they are manipulated 1 sample
* 5. You can use these arrays directly in a function
*
* $_GET // through URL Requests variables to be submitted to the script
* $_POST // through HTTP POST  Method is submitted to the script's variables
* $_REQUEST // through GET , POST and COOKIE Mechanism to submit   To script variables
* $_FILES // through http post A variable that is submitted to a script when the method file is uploaded
* $_COOKIE
* $_SESSION
* $_ENV // Variables that the execution environment commits to the script
* $_SERVER // Variables by WEB Of, or directly associated with, the execution environment of the current script
* $GLOBALS // Any variables that are valid for the current script are here, and the array key is the name of the global script
*
*
*/
// The superglobal array can be called directly from within the function
$arr=array(10,20);//1 As an array
$_GET=array(50,90);// Superglobal array
function demo(){
global $arr;// Global variables are called with inclusion first
print_r($arr);
print_r($_GET);// Direct calls to a superglobal array do not include
}
?>
<!-- ********** Page by value get request *************** -->
<?php
// Use the value directly as a variable , when php.ini In the configuration file register_global=on When useful.
echo $username."<br>";
echo $email."<br>";
echo $page."<br>";
// The most stable way to evaluate it
echo $_GET["username"]."<br>";
echo $_GET["email"]."<br>";
echo $_GET["page"]."<br>";
?>
<a href="demo.php?username=zhangsan&[email protected]&page=45">this is a $_GET test</a>
<!-- *********** Page by value post request **************** -->
<form action="demo.php" method="post">
username:<input type="text" name="uname" /> <br/>
password:<input type="password" name="pass" /> <br/>
<input type="submit" value="login" /> <br />
</form>
<?php
print_r($_GET);// Can't receive
print_r($_POST);// That's how you get it
?>
<?php
//$_ENV The use of
echo'<pre>';
print_r($_ENV);
echo'</pre>';
// Display the current environment
//  It can also be traversed individually
?>
<?php
// using $GLOBALS The super global array calls the global variable inside the function
$a=100;
$b=200;
$c=300;
function demo()
{
// Call global variables directly
echo $GLOBALS["a"]."<br>";
echo $GLOABLS["b"]."<br>";
echo $GLOABLS["c"]."<br>";
}
?>