paste a string to many column names using a function in R

I would like to rename many variable names using a function. For example, adding ‘demo’ to each one of the variable names for age, gender, but NOT for zipcode, addresses.

So far, I have:

 demo <- function(x)
  {
  data$demo_x <- data$x 
   }
  demo("age")
  demo("gender")

I’ve tried paste0 function and some suggestions below. However, I only want to change some of the variables – not all the variables in my dataset.

>Solution :

Using dplyr:

library(dplyr)

data |>
  rename_with(\(x) paste0("demo", x))

A benefit of using dplyr is rename_with allows you to use tidyselect syntax to only apply these name changes to a subset of columns (e.g. rename_with(\(x) paste0("demo", x), where(is.numeric)) to only rename numeric columns).

In base R:

names(data) <- paste0("demo", names(data))