r - Dealing with TRUE, FALSE, NA and NaN

Question

Here is a vector

a <- c(TRUE, FALSE, FALSE, NA, FALSE, TRUE, NA, FALSE, TRUE)

I'd like a simple function that returns TRUE everytime there is a TRUE in "a", and FALSE everytime there is a FALSE or a NA in "a".

The three following things do not work

a == TRUE
identical(TRUE, a)
isTRUE(a)

Here is a solution

a[-which(is.na(a))]

but it doesn't seem to be a straightforward and easy solution

Is there another solution ?

Here are some functions (and operators) I know:

identical()
isTRUE()
is.na()
na.rm()
&
|
!

• What are the other functions (operators, tips, whatever,...) that are useful to deal with TRUE, FALSE, NA, NaN?

• What are the differences between NA and NaN?

• Are there other "logical things" than TRUE, FALSE, NA and NaN?

Thanks a lot !

Answer 1

You don't need to wrap anything in a function - the following works

a = c(T,F,NA)

a %in% TRUE

[1]  TRUE FALSE FALSE