R replace multiple column value from another dataframe

Question

first dataframe like this, with quite few columns:

name	C1	C2	C3	....
a	2	3	5	.....
b	4	5	6	....
c	6	2	3	....

second dataframe like this:

id	C_name
2	apple
3	banana
4	orange
5	grape
6	kiwi

I would like to replace the numbers in the first dataframe with the names in second dataframe, it should look like this

name	C1	C2	C3	....
a	apple	banana	grape	.....
b	orange	grape	kiwi	....
c	kiwi	apple	banana	....

thank you

Answer 1

dat2vec <- setNames(dat2$C_name, dat2$id)
dat1[2:4] <- lapply(dat1[2:4], function(z) dat2vec[as.character(z)])
dat1
#   name     C1     C2     C3  ....
# 1    a  apple banana  grape .....
# 2    b orange  grape   kiwi  ....
# 3    c   kiwi  apple banana  ....

or

dat1[2:4] <- lapply(dat1[2:4], function(z) {
  ind <- match(z, dat2$id)
  replace(z, !is.na(ind), dat2$C_name[ind])
})

---

Data

dat1 <- structure(list(name = c("a", "b", "c"), C1 = c("apple", "orange", "kiwi"), C2 = c("banana", "grape", "apple"), C3 = c("grape", "kiwi", "banana"), .... = c(".....", "....", "....")), row.names = c(NA, -3L), class = "data.frame")
dat2 <- structure(list(id = 2:6, C_name = c("apple", "banana", "orange", "grape", "kiwi")), class = "data.frame", row.names = c(NA, -5L))