[R] Return value from function with For loop

[jim holtman]

In the first case you have a "for" and it is the statement after the
'for' that is the return value and it is a NULL.  For example:

> print(for (i in 1:4) i+1)
NULL

In the second case, the last statement if the expression '(n+1)' which
give you the correct value:

> xx <- function(n) n+1
> print(xx(3))
[1] 4
>




Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.


On Sun, Apr 16, 2017 at 10:26 PM, Ramnik Bansal <ramnik.bansal at gmail.com> wrote:
> In the code below
>
>
> *ff <- function(n){ for(i in 1:n) (i+1)}*
>
> *n<-3;ff(n)->op;print(op)*
>
> Why doesnt *print(op) * print 4 and instead prints NULL.
> Isnt the last line of code executed is *i+1 * and therefore that should be
> returned instead of NULL
>
> instead if I say
> *ff <- function(n){ (n+1) }*
>
> Then
> *n<-3;ff(n)->op;rm(n);print(op)*
> gives 4 as output.
>
> My question is *Which *is considered as the last line in a functoin for the
> purpsoe of default return ? And under what conditions ?
>
> -Thanks,
> Ramnik
>
>         [[alternative HTML version deleted]]
>
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