How to check if each element in a vector is integer or not in R?

Question

Say, I have a vector y, and I want to check if each element in y is integer or not, and if not, stop with an error message. I tried is.integer(y), but it does not work.

Answer 1

checking the following helps with a crisp if condition which we can use on scripting.

sff <- 5

if(!(is.integer(sff) == is.character(sff))){ 
  sff
} else {
  "hello"
}

gives

hello

sff <- 'a' gives 'a' as the result.