Counting non NAs in a data frame; getting answer as a vector

Question

Say I have the following R data.frame ZZZ:

( ZZZ <- structure(list(n = c(1, 2, NA), m = c(6, NA, NA), o = c(7, 8, 
8)), .Names = c(\         


        

Answer 1

For getting total no of missing values use sum(is.na(x)) and for colum-wise use colSums(is.na(x)) where x is varible that contain dataset