What is an example that is not a functor?

[FredericChow00]

a functor is associative where

functor.map(g.compose(h)) ≡ functor.map(h).map(g)

Is anyone able to give me an example where a context is not functor?

Wouldn't every functor the does functor.map(g.compose(h)) always be equal to functor.map(h).map(g)?

For example if g is x -> x * 2
h is x -> x + 2

both left and right side give the same result

[RyanTYT]

I believe if you add something wonky like below as the map function, then it wouldn't be a functor

class functor<...> {
    ...
    map(Function<..., ...> mapper) {
        return mapper.apply(mapper.apply(this.x));
    }
}

[yewey2]

that's true, if it's wonky just check the results!

alternatively as an example, for functors that deal specifically with integers

class Functor<Integer> {
    ...
    map(Function<..., ...> mapper) {
        return mapper.apply(x) + 1;
    }
}

let g = x -> x + 2 and h = x -> x * 2
and functor = new Functor(1)
functor.map(h).map(g) = (1 * 2 + 1) + 2 + 1 = 3 + 3 = 6
functor.map(g.compose(h)) = ((1 * 2) + 2) + 1 = 4 + 1 = 5

[FredericChow00]

I see! Thanks so much for all the replies, I understand now