PHP Superglobals

superglobals : 함수, 클래스, 파일, 스코프와 관계 없이 언제나 접근 가능한 PHP built-in변수.

$GLOBALS : 모든 글로벌 변수를 담는 배열

<?php
$x = 75;
$y = 25;
  
function addition() {
$GLOBALS['z'] = $GLOBALS['x'] + $GLOBALS['y'];
}
  
addition();
echo $z;
?>

$_SERVER : header, paths, script location정보를 담는 배열

<?php
echo $_SERVER['PHP_SELF'];
echo $_SERVER['SERVER_NAME'];
echo $_SERVER['HTTP_HOST'];
echo $_SERVER['HTTP_REFERER'];
echo $_SERVER['HTTP_USER_AGENT'];
echo $_SERVER['SCRIPT_NAME'];
?>
//https://www.w3schools.com/php/php_superglobals_server.asp

$_REQUEST : HTML폼 submit이후 데이터를 collect

<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;
        }
    }
?>

$_POST : HTML폼 submit이후 데이터를 collect (POST방식)

<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 = $_POST['fname'];
        if (empty($name)) {
            echo "Name is empty";
        } else {
            echo $name;
        }
    }
?>

$_GET : HTML폼 submit이후 데이터를 collect (GET방식). URL로 받는 정보도 가져올 수 있다

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

    <?php
    echo "Study " . $_GET['subject'] . " at " . $_GET['web'];
    ?>

$_FILES
$_ENV
$_COOKIE
$_SESSION

PHP SuperGlobals

PHP Superglobals

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