dplyr rename error: contains unknown variables

Question

Very simple, renaming colnames with dplyr gives me an odd error.

 library(dplyr)

 df <- data.frame(var1=c("one","two","three"),var2=c(1,2,3)) 

 df <- 
    df %>% 
    rename(var1=are.letters, var2=are.numbers)

Error: `are.letters`, `are.numbers` contains unknown variables

second try

 df <- rename(df, var1=are.letters, var2=are.numbers)

Error: `are.letters`, `are.numbers` contains unknown variables

Wondering if quoting....

df <- 
    df %>% 
    rename('var1'='are.letters', 'var2'='are.numbers')

Error: `are.letters`, `are.numbers` contains unknown variables

Answer 1

Just made the same error. So, I'm converting @akrun's useful comment into an "answer."

To fix this, the new name should be on the left hand of the equal sign and the existing name should be on the right.

Like this:

df <- df %>% 
    rename(are.letters = var1, are.numbers = var2)