Algebra - function

I have rewatch function videos a few times but I think I roughly got the idea though I always somehow get it wrong when required to transform a function.

For this particular question, is it correct to always say whenever the given f(x) = f(x+2), regardless of the input, it will always be be 2 because f(4) = 2 and due to f(x+2)? in other words, if f(x) = f(x+20-10+20) and if f(4) = 2, for any input, the output will always be 2?

For any even input. Otherwise you don’t know.