> "this" refers to the Sprite that invoked the function
Sure, "this" is always what invoked the function. Why not just pass in the sprite to the function though and use the argument instead? That makes the learning more general for all languages and not javascript specific. IMO, there is no value in using "this".
I don't think OOP should be taught in the early stages of learning programming. Here is a simple example from the docs:
let stage = new blockLike.Stage();
let sprite = new blockLike.Sprite();
sprite.addTo(stage);
Why are you adding a stage to a sprite instead of adding a sprite to a stage? Why does sprite have a method defined on it and why is stage the parameter? I think a more consistent way to do that would be to have a function that takes both as arguments:
addSpriteToStage(sprite, stage);
Imagine that the person trying to learn programming is trying to come up with their own library to use. It wouldn't even occur to them to create free standing function. Instead they would have to waste time deciding which arbitrary class to put the method on.
> It can be rewritten without using "this" (obviously). But can you make it easier to understand?
Here is a simple change I would make for that example. I can't figure out how to share the codepen (I think creating an account might be the only way) so here's the code for the relevant part:
function myFunction(sprite) {
sprite.say('hi');
sprite.wait(1);
sprite.sayWait('bye', 1);
sprite.say('')
}
sprite1.whenClicked(function() {
myFunction(sprite1);
});
sprite2.whenClicked(function() {
myFunction(sprite2);
});
Unfortunately this doesn't work. I have no idea what magic that "invoke" function does, so I don't know why this doesn't work. What if you wanted the other sprite to talk when a sprite is clicked? Wouldn't you have to pass in an argument anyway. Getting a magical "this" when it happens to be the sprite that is clicked that is doing the talking seems arbitrary.
Anyway, I guess my biggest gripe is that it puts too much emphasis on OOP too early in the process of learning to program.