To be precise most array languages are not functional, although they do support "function-level programming" - the distinction is not clear to me just yet, but I hope to improve. :)
The K language, which presumably incorporates parts of Scheme, is a notable exception to this.
Like the original FP/FL languages, J supports function-level programming via its tacit programming features (note that function-level programming is not the same as functional programming).
As I said, it's unclear to me what the difference is, but that's what I based my previous comment on.
That sentence only means to say that J supports function-level programming, which itself is different from functional programming. The very same Wikipedia page also calls J a functional language -- the fact that it supports function-level programming doesn't contradict the fact that it also supports functional programming.
The K language, which presumably incorporates parts of Scheme, is a notable exception to this.