In the R FAQ's section about comparing S and R, we find the following:
In R, For() loops are not necessary and hence not supported.
What was a For()
loop and why does R not need it?
There is a copy of S-PLUS: Programmer’s Guide online. Pages 647-648 contrast for
and For
loops. The S-Plus manual generally discourages using for
loops (pp. 120, 639-641) and encourages apply
family approaches, but R has optimized for
loops to the point that those recommendations are now moot and the "optimized" For
loop is no longer necessary.