x
music_genre <- factor(c("Jazz", "Rock", "Classic", "Classic", "Pop", "Jazz", "Rock", "Jazz"))music_genre[3] <- "Opera"music_genre[3]Warning message: In `[<-.factor`(`*tmp*`, 3, value = "Opera") : invalid factor level, NA generated
music_genre <- factor(c("Jazz", "Rock", "Classic", "Classic", "Pop", "Jazz", "Rock", "Jazz"))music_genre[3] <- "Opera"music_genre[3]Warning message: In `[<-.factor`(`*tmp*`, 3, value = "Opera") : invalid factor level, NA generated