Why does an empty dataframe fail an is.null() test?

Question

please excuse me if my question is quite basic. I created an empty data frame by df <- data.frame() and obviously the data frame is NULL (empty). when I try to

Answer 1

Above answers are correct, is.na and is.null couldn't not detect empty value in R. This is what I would do to calculate how many empty value you have in your data frame 'df' in this case.

is.na(df[df =='']) <- TRUE # this just replace NA to the empty value in df.

sum(is.na(df)) # would give you an idea how many empty values you have in your 'df'.

Hope this is helpful.