Create an ID (row number) column

Question

I need to create a column with unique ID, basically add the row number as an own column. My current data frame looks like this:

   V1  V2
1  23  45
2  45  4         


        

Answer 1

Many presented their ideas, but I think this is the sortest and simplest code for this task:

data$ID <- 1:nrow(data)

One line. The one and only.