[R] where does the null come from?

[K. Elo]

Hi!

Wacek Kusnierczyk wrote:
>     m = matrix(1:4, 2)
> 
>     apply(m, 1, cat, '\n')
>     # 1 2
>     # 3 4
>     # NULL
> 
> why the null?

Could it be the return value of 'cat'. See ?cat, where:

---snip ---
Value
 None (invisible NULL).
---snip ---

Kind regrads,
Kimmo