$ _POST突然抛出错误[重复]

I have this code that checks for login. It has been working fine but just stopped working suddenly.

public function checkLogin($_POST) {
        // fetching user by email
        $stmt = $this->conn->prepare("SELECT password_hash FROM users WHERE email = ?");

        $stmt->bind_param("s", $email);

        $stmt->execute();

        $stmt->bind_result($password_hash);

        $stmt->store_result();

        if ($stmt->num_rows > 0) {
            // Found user with the email
            // Now verify the password

            $stmt->fetch();

            $stmt->close();

            if (PassHash::check_password($password_hash, $password)) {
                // User password is correct
                return TRUE;
            } else {
                // user password is incorrect
                return FALSE;
            }
        } else {
            $stmt->close();

            // user not existed with the email
            return FALSE;
        }
    }

After checking my apache error log, I am seeing this error:

PHP Fatal error:  Cannot re-assign auto-global variable _POST

Any work around this?

</div>

Since PHP 5.4, you cannot use a superglobal as the parameter to a function

$_POST is globally accessible. So you don't have to pass to your function.

This is how your function should look like

public function checkLogin() {
$email = $_POST['email'];
$password = $_POST['password'];

        // fetching user by email
        $stmt = $this->conn->prepare("SELECT password_hash FROM users WHERE email = ?");

        $stmt->bind_param("s", $email);

        $stmt->execute();

        $stmt->bind_result($password_hash);

        $stmt->store_result();

        if ($stmt->num_rows > 0) {
            // Found user with the email
            // Now verify the password

            $stmt->fetch();

            $stmt->close();

            if (PassHash::check_password($password_hash, $password)) {
                // User password is correct
                return TRUE;
            } else {
                // user password is incorrect
                return FALSE;
            }
        } else {
            $stmt->close();

            // user not existed with the email
            return FALSE;
        }
    }

That is because $_POST is a superglobal. From Superglobals on PHP.net:

Since PHP 5.4, you cannot use a superglobal as the parameter to a function. This causes a fatal error:

function foo($_GET) {
   // whatever
}

It's called "shadowing" a superglobal, and I don't know why people ever did it, but I've seen it out there. The easy fix is just to rename the variable $get in the function, assuming that name is unique.

You can access $_POST from within the function:

function foo(){
    print_r($_POST);
}

Or you can pass $_POST to a function like so:

foo($_POST);

function foo($post){
    print_r($post);
}

$_POST is superglobal variable. Why are you passing it in parameter. You can directly use it in function like this :

public function checkLogin() {
     print_r($_POST);
     //your rest of code
}