Error in if/while (condition) {: missing Value where TRUE/FALSE needed

Question

I received this error message:

Error in if (condition) { : missing value where TRUE/FALSE needed

or

Error in while (conditi         


        

Answer 1

this works with "NA" not for NA

comments = c("no","yes","NA")
  for (l in 1:length(comments)) {
    #if (!is.na(comments[l])) print(comments[l])
    if (comments[l] != "NA") print(comments[l])
  }