Catch integer 0 in R

Question

Consider a statement that produces integer(0)

For example:

 a <- which(1:3 == 5)

Which is the safest way of catching this?

Answer 1

R's way of printing a zero length vector(an integer one). So you could test for length 0

length(a)
[1] 0

I suggest you not to use which, and try using the above method

It might be worth rethinking the strategy you are using to identify which elements you want, but without further specific details it is difficult to suggest an alternative strategy.