Compare values beween 2 columns and return value of a third column

In a dataframe we have:

I would like to create a Column D based on the following logic: match each column C value with column B and return the value of Column A that corresponds to the position of the matched value.

in this case it would look like this:

I have tried the following:

data<-data %>% 
      mutate(D = case_when(C%in%B~A))

but it returns the value of column A that matches column B and not column C.

>Solution :

You can use match,

df$ColumnD <- df$ColumnA[match(df$ColumnC, df$ColumnB)]
#[1] "G" "F" "E"

Or in dplyr

library(dplyr)

df %>% 
 mutate(ColumnD = ColumnA[match(ColumnC, ColumnB)])

  ColumnA ColumnB ColumnC ColumnD
1       E       1       3       G
2       F       2       2       F
3       G       3       1       E

DATA

dput(df)
structure(list(ColumnA = c("E", "F", "G"), ColumnB = 1:3, ColumnC = 3:1), class = "data.frame", row.names = c(NA, 
-3L))