Select the last n columns of data frame in R

Question

Is there a way to systematically select the last columns of a data frame? I would like to be able to move the last columns to be the first columns, but maintain the order of

Answer 1

data frames are just lists, so you can rearrange them as you would any list:

newdata <- c(mydata[colNamesToStart],
             mydata[-which(names(mydata) %in% colNamesToStart)])