How can I overwrite data-CodePudding

I have two datasets. The 1st one is:

Column_A
3
4
1
6

and the 2nd one looks like this:

Column_B	Column_C
1	a
2	b
3	c
4	d
5	e
6	f

How can I overwrite Column_A from the 1st data frame with observation in Column_C if the value of Column_A is identical as the value of Column_B?

My result should look like this:

Column_A
c
d
a
f

Thanks in advance!

CodePudding user response：

You can use match to find the index of column B that matches each entry in column A. Just subset column C by this.

df1$Column_A <- df2$Column_C[match(df1$Column_A, df2$Column_B)]

df1
#>   Column_A
#> 1        c
#> 2        d
#> 3        a
#> 4        f

Reproducible data

df1
#>   Column_A
#> 1        3
#> 2        4
#> 3        1
#> 4        6

df2
#>   Column_B Column_C
#> 1        1        a
#> 2        2        b
#> 3        3        c
#> 4        4        d
#> 5        5        e
#> 6        6        f