Lesson 13 Extra *extra extra* Challenge


Anyone ever give the students an extra challenge of trying to figure out how to keep the rectangle from never leaving the screen. I feel this would be a good key learning as if you were designing a game and say the rectangle was a character I feel you would never want any part of it at all to leave the screen.

Anyways hope this makes sense and here is a solution to this…

// Create a sprite
var sprite = createSprite(200, 100, 50, 50);
sprite.shapeColor = “red”;

function draw() {

// Move the sprite in the direction of the arrow keys
// But make sure it doesn’t go off the screen
if (keyDown(“up”) && sprite.y > 25) {
sprite.y = sprite.y - 5;
if (keyDown(“down”) && sprite.y < 375) {
sprite.y = sprite.y + 5;
if (keyDown(“left”) && sprite.x > 25) {
sprite.x = sprite.x - 5;
if (keyDown(“right”) && sprite.x < 375) {
sprite.x = sprite.x + 5;



One thing I just realized though you have to consider is how much you are increasing the sprite by. As you can see I sped up the sprite by doing +5 as I was getting sick of how slow it was going. However, if I do more then +5 it will actually still fall off the screen in my scenario.

Lot of different things you have to think about and consider when your making these.



Yep! As I started making challenges for my students I realized those little things too. Glad to see you are working through it!


PS also responded to your other post here: Lesson 13 Extra *extra* Challenge