library(dplyr)
library(data.table)
DT <- data.table(
  name = c("小明", "小明", "小英", "小美"),
  age = c(18, 18, 11, 22),
  gender = c("男", "男", "女", "女"),
  status = c("大學生", "大學生", "小學生", "大學生"),
  date = c("5/1", "5/3", "5/1", "5/4"),
  schedule = c("打球", "上課", "游泳", "唱歌"))
class(DT)


## 同Data.frame
DT1 <- DT %>%
  group_by(name, age, gender, status) %>% 
  summarise(date = paste(date, collapse = ","),
            schedule = paste(schedule, collapse = ","))
class(DT1) ## Tibble
DT1
## 
DT2 <- DT[, .(date = paste(date, collapse = ","),
          schedule = paste(schedule, collapse = ",")),
   by = list(name, age, gender, status)]
class(DT2) ## data.table
DT2

## 
library(tibble)
TBL <- tibble(
  name = c("小明", "小明", "小英", "小美"),
  age = c(18, 18, 11, 22),
  gender = c("男", "男", "女", "女"),
  status = c("大學生", "大學生", "小學生", "大學生"),
  date = c("5/1", "5/3", "5/1", "5/4"),
  schedule = c("打球", "上課", "游泳", "唱歌"))
class(TBL)

TBL1 <- TBL %>%
  group_by(name, age, gender, status) %>% 
  summarise(date = paste(date, collapse = ","),
            schedule = paste(schedule, collapse = ","))
class(TBL1)
TBL1
# your code goes here