如何将变量声明为全局变量，以便可以在任何函数中使用

Question

How to declare a variable as global variable so it can be use inside any function. I want the db connect variable $connect. In my function the $connect variable is not working as they are in the same page.

Here is my db connect code

$localhost = "localhost";
$username = "root";
$password = "";
$dbname = "xxxxxxxx";

// create connection
$connect = new mysqli($localhost, $username, $password, $dbname);

// check connection
if($connect->connect_error) {
    die("connection failed : " . $connect->connect_error);
}

and here is my Function

function secureInput($var){
    global $connect;
    $output = '';
    if (is_array($var)){
        foreach($var as $key=>$val){
            $output[$key] = secureInput($val);
        }
    } else {
        $var = strip_tags(trim($var));
        if (function_exists("get_magic_quotes_gpc")) {
            $output = mysqli_real_escape_string($connect,get_magic_quotes_gpc() ? stripslashes($var) : $var);
        } else {
            $output = mysqli_real_escape_string($connect,$var);
        }
    }
    if (!empty($output))
    return $output;
}

want to use that function as like bellow to secure input. If there is any other solution please help me to fix this.

$username = secureInput($_POST['username']);
$password = secureInput($_POST['password']);

Answer 1

Declaration:

$GLOBALS['varName'] = "varContent";

Usage:

echo $GLOBALS['varName'];