Extract last non-missing value in row with data.table

Question

I have a data.table of factor columns, and I want to pull out the label of the last non-missing value in each row. It\'s kindof a typical max.col situation, bu

Answer 1

Here is a one liner base R approach:

sapply(split(dat, seq(nrow(dat))), function(x) tail(x[!is.na(x)],1))
#  1   2   3   4   5   6   7   8 
#"u" "q" "w" "h" "r" "t" "e" "t"