add new column based on two other columns with several conditions, character

I like case_when from dplyr for these types of complex conditionals.

df<-tibble::tribble(
   ~job, ~honorary,
  "yes",     "yes",
  "yes",      "no",
   "no",     "yes",
  "yes",     "yes",
  "yes",        NA,
     NA,      "no"
  )

library(dplyr)

df_new <- df %>%
  mutate(result=case_when(
    job=="yes" & honorary=="yes" ~ "both",
    honorary=="yes" ~ "honorary", 
    job=="yes" ~ "job", 
    is.na(honorary) & is.na(job) ~ NA_character_, 
    is.na(honorary) & job=="no" ~ NA_character_, 
    is.na(job) & honorary=="no" ~ NA_character_, 
    TRUE ~ "other"
  ))

df_new
#> # A tibble: 6 × 3
#>   job   honorary result  
#>   <chr> <chr>    <chr>   
#> 1 yes   yes      both    
#> 2 yes   no       job     
#> 3 no    yes      honorary
#> 4 yes   yes      both    
#> 5 yes   <NA>     job     
#> 6 <NA>  no       <NA>

or in base R

df_new<-df

df_new=within(df_new,{
  result=NA
  result[ honorary=="yes"] = "honorary"
  result[ job=="yes"] = "job"
  result[job=="yes" & honorary=="yes"]='both'
})

^{Created on 2022-01-16 by the reprex package (v2.0.1)}