Can I use the parameter in the function and echo it out in the if statement below

I am experiencing a problem where I can’t use the parameter in the function in other functions more specifically the $studentnumber parameter, is it possible for the parameters used in other functions, the parameter used were dynamic parameter. I’m new to PHP so my terminology might be off I the end goal is to make $studentnumber, able to be used in other functions.

public function login($studentnumber, $password) {
            $conn = dbconnection();
            $stmt = $conn->prepare("SELECT * FROM login WHERE studentnumber = :studentnumber");
            $stmt->bindParam(':studentnumber', $studentnumber);
            $stmt->execute();
            $row = $stmt->fetch();
            if ($password == $row['password']) {
                echo $studentnumber;
                return true;
            } else {
                return false;
            }
        }

public function login($studentnumber, $password) {
            $this->studentnumber = $studentnumber;
            $conn = dbconnection();
            $stmt = $conn->prepare("SELECT * FROM login WHERE studentnumber = :studentnumber");
            $stmt->bindParam(':studentnumber', $studentnumber);
            $stmt->execute();
            $row = $stmt->fetch();
            if ($password == $row['password']) {
                echo $this->studentnumber;
                return true;
            } else {
                return false;
            }
        }