How to write a function for a specific direction?

I am trying to write a function that make my arrow point to true north regardless of which way its point at a certain point of time. So far I have (Code below). Everytime I run it it tells me I have to many input arugements. Im not sure if im writing this correctly.

function turnNorth()

(getHeading(2))

turnLeft();

(getHeading(3))

turnLeft();

turnLeft();

(getHeading(4))

turnLeft();

turnLeft();

turnLeft();

end

Answer 1

[Walter Roberson]

My guess is that you need

function turnNorth()
current_heading = getHeading;
switch current_heading
    case 2:
        turnLeft(); 
    case 3:
        turnLeft();
        turnLeft();
    case 4:
        turnLeft();
        turnLeft();
        turnLeft();   
end