在mutate中使用stringr中的str_to_title，你可以 "convert case" 你的变量，然后你可以使用count来计算每个甜点的观察次数。

代码

library(dplyr)
library(stringr)
   

df <- data.frame(sweets= c("cookie", "CANDY", "Cookie", "cake", "IceCream", "Candy", "Chocolate", "COOKIE", "CAKE"))

df %>% 
  mutate(sweets = str_to_title(sweets)) %>%
  count(sweets)

输出

sweets n
1      Cake 2
2     Candy 2
3 Chocolate 1
4    Cookie 3
5  Icecream 1

全部转换为小写，然后转换为 table：

table(tolower(df$sweets))
# cake     candy chocolate    cookie  icecream 
#    2         2         1         3         1

或者?tolower提供了一个辅助函数- capwords：

capwords <- function(s, strict = FALSE) {
  cap <- function(s) paste(toupper(substring(s, 1, 1)),
                           {s <- substring(s, 2); if(strict) tolower(s) else s},
                           sep = "", collapse = " " )
  sapply(strsplit(s, split = " "), cap, USE.NAMES = !is.null(names(s)))
}

table(capwords(df$sweets, strict = TRUE))
# Cake     Candy Chocolate    Cookie  Icecream 
#    2         2         1         3         1