[R] is.null(mylist[1]) and is.null(mylist$a) returns different values

[Huzefa Khalil]

Hi,

Try

> is.null(mylist[[1]])
[1] TRUE

Notice the double square brackets.

From: ?`[`
"The most important distinction between [, [[ and $ is that the [ can
select more than one element whereas the other two select a single
element."

On Thu, Jun 15, 2017 at 11:33 AM, ce <zadig_1 at excite.com> wrote:
> Hi
>
> I have a list :
>
> mylist <- list( a = NULL, b = 1, c = 2 )
>
>> mylist[1]
> $a
> NULL
>
>> is.null(mylist[1])
> [1] FALSE
>
>> is.null(mylist$a)
> [1] TRUE
>
> why? I need to use mylist[1]
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-- 
Huzefa Khalil
PhD Candidate,
Department of Political Science,
University of Michigan