What's an example of a function whose domain consists of 5 numbers and range consists of three numbers?

And an example of a function whose domain is a set of real numbers and whose range is not on an interval

Question

What's an example of a function whose domain consists of 5 numbers and range consists of three numbers?

And an example of a function whose domain is a set of real numbers and whose range is not on an interval

anonymous · Answer

$$
f(x) = x^2
$$With the domain of $\{-2,-1,0,1,2\}$

anonymous · Answer

It ends up with a range for $\{0,1,4\}$

anonymous · Answer

would something like |x| work too?

anonymous · Answer

Yes

anonymous · Answer

You can even say: $$
f :=\{(1,1),(2,2),(3,3),(4,1),(5,1)\}
$$

anonymous · Answer

what about an example of a function whose domain is a set of real numbers and whose range is not on an interval?

anonymous · Answer

That wouldn't work because it's domain and range would be too large.