Can't count the null values of a dataframe in R

NULL and NA are distinct. NULL means "not defined" and NA means "missing". The screenshot and the output of colSums() show that some NAs are present.


will return the total number in the data frame.


gives the count of NA by column, and


shows the rows containing NA.


isn't working, we'd need to look at a representative data set. See the FAQ: How to do a minimal reproducible example reprex for beginners.