intX = 0
intY = 0
operator = "+"

function bepaalOperator()
    if Keys.newPress.A then
        operator = "+"
    elseif Keys.newPress.B then
        operator = "-"
    elseif Keys.newPress.X then
        operator = "*"
    elseif Keys.newPress.Y then
        operator = "/"
    end
end

function bepaalWaarde()
    if Keys.newPress.Up then
        intX = intX+1
    elseif Keys.newPress.Down then
        intX = intX-1
    elseif Keys.newPress.Left then
        intY = intY+1
    elseif Keys.newPress.Right then
        intY = intY-1
    end
end

--Deze functie zorgt voor de berekening
function berekenSom(parX, parY)
    if operator == "+" then
        berekening = (parX + parY)
    elseif operator == "-" then
        berekening = (parX - parY)
    elseif operator == "*" then
        berekening = (parX * parY)
    elseif operator == "/" then
        berekening = (parX / parY)
    end
    return berekening
end


--Deze functie zorgt voor de zichtbare tekst op het scherm
function drawScreen()
    screen.startDrawing()
    screen.print(SCREEN_UP,0,0,"Press START to stop")
    screen.print(SCREEN_UP,0,10,"Press A,B,X,Y to change the operator")
    screen.print(SCREEN_UP,0,20,"Press Arrow keys to change the variables")

    screen.print(SCREEN_DOWN,10,100,"x: "..intX)
    screen.print(SCREEN_DOWN,10,110,"y: "..intY)
    screen.print(SCREEN_DOWN,10,120,"operator: "..operator)
    screen.print(SCREEN_DOWN,10,130,"Het antwoord op de berekening is "..berekenSom(intX,intY))
    screen.stopDrawing()
end

while not Keys.newPress.Start do
    Controls.read()
    bepaalOperator()
    bepaalWaarde()
    drawScreen()
end