如何从函数中获取字符串

So, this is my code:

class Functions{
    public static function login($email,$password){
        $email = $_GET['email'];
        $password = $_GET['password'];
        if(isset($_GET['submit']) AND isset($email) AND isset($password)){
            $password = md5($password);
            $sql = "SELECT * FROM users WHERE email='$email' AND password='$password'";
            $result = $conn->query($sql);
            if ($result->num_rows > 0) {
                $row = $result->fetch_assoc();
                $_SESSION['nume'] = $row["name"];
                $_SESSION['uid'] = $row["id"];
                $_SESSION['admin'] = $row["admin"];
                $_SESSION['email'] = $row["email"];
                $_SESSION['points'] = $row["points"];
            }else{
                $errortxt = "Invalid Login Credentials";
                $error = true;
            }
        }
        return $error;
    }
}

In my HTML file I'm calling for the function like this:

Function::login($email,$password);

But I'm wondering how can I get the $errortxt string to echo in the HTML file.

Thanks!

You just need a simple fix:

class Functions{
public static function login($email,$password){
    $response['error'] = false;
    $response['errortxt'] = "";
    $email = $_GET['email'];
    $password = $_GET['password'];
    if(isset($_GET['submit']) AND isset($email) AND isset($password)){
        $password = md5($password);
        $sql = "SELECT * FROM users WHERE email='$email' AND password='$password'";
        $result = $conn->query($sql);
        if ($result->num_rows > 0) {
            $row = $result->fetch_assoc();
            $_SESSION['nume'] = $row["name"];
            $_SESSION['uid'] = $row["id"];
            $_SESSION['admin'] = $row["admin"];
            $_SESSION['email'] = $row["email"];
            $_SESSION['points'] = $row["points"];
        }else{
            $response['error'] = true;
            $response['errortxt'] = "Invalid Login Credentials";
        }
    }
    return $response;
}
}

And you need to call it this way:

$fnCallStatus = Function::login($email,$password); //Now you have the response;
if($fnCallStatus['error']) //we have an error
{
    echo $fnCallStatus['errortxt']; //we print the message
}

Hi I fixed little bit your code because it lacks good coding principles and good taste (calling superglobal $_GET variable will always get you something after request despite you place something else into function parameters).

class Functions{

    public static function login($email,$password)
    {
        $error['is'] = true;

        $email = htmlspecialchars($email);
        $password = md5(htmlspecialchars($password));

        if(!empty($email) AND !empty($password))
        {
            $sql = "SELECT * FROM users WHERE email='$email' AND password='$password'";
            $result = $conn->query($sql);
            if ($result->num_rows > 0)
            {
                $row = $result->fetch_assoc();
                $_SESSION['nume'] = $row["name"];
                $_SESSION['uid'] = $row["id"];
                $_SESSION['admin'] = $row["admin"];
                $_SESSION['email'] = $row["email"];
                $_SESSION['points'] = $row["points"];
            } else {
                $error['mismatch'] = "Email or password does not match.";
                return $error;
            }
        } else {
            $error['empty'] = "Please fill all login fields. Thank you";
            return $error;
        }
    }
}

$error = Function::login($_GET['email'],$_GET['password']);

if($error['is'])
{
    if ($error['mismatch']) {
        echo $error['mismatch'];
    } elseif ($error['empty']) {
        echo $error['empty']
    }
}

Your function also always return $error despite none occurred. I fixed that and function return error only in not query case.

Functions can return arrays. So if you need to set multiple fields with different text, you can place into array anything you like. This solution is more buletproof.