Convert all character columns to factors using dplyr in R

character2factor.r

library(dplyr)
iris_char <- iris %>%
  mutate(Species=as.character(Species),
         char_column=sample(letters[1:5], nrow(iris), replace=TRUE))
sum(sapply(iris_char, is.character)) # 2

iris_factor <- iris_char %>%
  mutate_if(sapply(iris_char, is.character), as.factor)
# Sepal.Length  Sepal.Width Petal.Length  Petal.Width      Species  char_column 
# "numeric"    "numeric"    "numeric"    "numeric"  "character"  "character" 

sapply(iris_factor, class)
# Sepal.Length  Sepal.Width Petal.Length  Petal.Width      Species  char_column 
# "numeric"    "numeric"    "numeric"    "numeric"     "factor"     "factor" 

Is sapply necessary here? I think
iris_factor <- iris %>% mutate_if(is.character,as.factor)
works just as well.

This works fine!

This worked beautifully, can't believe I didn't have this in my code before! I pull from a oracle database that default assigns every column to either int or chr, and this add-on allows me to do quick QA to make sure all the appropriate rows were pulled and none were dropped. Thank you!

Does this work while using case_when also? Thanks :)

Thanks a lot! I had a similar problem. It works beautyfully , but there was a complaint that mutate_if is deprecated. I changed it to the new syntax:
iris_factor <- iris %>% mutate(across(where(is.character), as.factor))