Move a column to first position in a data frame

Question

I would like to have the last column of the data frame moved to the start (as first column). How can I do it in R?

My data.frame has about a thousand columns to chan

Answer 1

If you want to move any named column to the first position, simply use:

df[,c(which(colnames(df)=="desired_colname"),which(colnames(df)!="desired_colname"))]