Loop over multiple character columns to derive a new variable
Solution 1:
dplyr
You may use rowwise and c_across:
testa %>%
rowwise() %>%
mutate(available = ifelse(any(c_across(a1:a4) == "yellow"), "yes", "no"))
a1 a2 a3 a4 available
<chr> <chr> <chr> <chr> <chr>
1 orange red black red no
2 red yellow orange brown yes
base R
Use apply:
testa$available <- apply(testa, 1, function(x) ifelse(any(x == "yellow"), "yes", "no"))