Refer to the last column in R

Question

I am trying to do some manipulation on the last column in a generic way.

I found here on the forums this nice piece of code that returns the name of the last columns:

tail(names(train),1) #returns [1] "last" 

I still can't figure out how to reference directly to my dataset's last columns as:

data$last

Answer 1

just use ncol() to get the index of the last col

data[,ncol(data)] 

Answer 2

Take the first element of the reversed vector of column names:

rev(names(mtcars))[1] [1] "carb" 

Similarly, to get the last column, you can use

rev(mtcars)[1]