How to rename selected columns using dplyr with new column names as strings

Question

I have the following tibble:

library(tidyverse)
df <- structure(list(Sepal.Length = c(5.1, 4.9, 4.7, 4.6, 5), Sepal.Width = c(3.5, 
3, 3.2, 3.1, 3.6), Pet         


        

Answer 1

df %>% setNames(paste0(names(.), to.app))

# A tibble: 5 × 3
  Sepal.Length.xxx Sepal.Width.xxx Petal.Length.xxx
*                                   
1              5.1             3.5              1.4
2              4.9             3.0              1.4
3              4.7             3.2              1.3
4              4.6             3.1              1.5
5              5.0             3.6              1.4

EDIT:

Apologies for not reading properly. Here's a solution with data.table package.

var <- names(df)[c(1,3)]
df %>% setnames(., var, paste0(var, to.app))
df

# A tibble: 5 × 3
  Sepal.Length.xxx Sepal.Width Petal.Length.xxx
*                               
1              5.1         3.5              1.4
2              4.9         3.0              1.4
3              4.7         3.2              1.3
4              4.6         3.1              1.5
5              5.0         3.6              1.4