Turn names into numbers in a dataframe based on the row index of the name in another dataframe

Question

I have two dataframes. One is just the names of my facebook friends and another one is the links with a sorce and target columns. I want to turn the names in the links dataframe to numbers based on the row index of that name in the friends dataframe.

friends

               name
1    Andrewt Thomas
2     Robbie McCord
3 Mohammad Mojadidi
4       Andrew John
5     Professor Owk
6    Joseph Charles

links

     source          target
1 Andrewt Thomas     Andrew John
2 Andrewt Thomas       James Zou
3  Robbie McCord         Bz Benz
4  Robbie McCord Yousef AL-alawi
5  Robbie McCord  Sherhan Asimov
6  Robbie McCord     Aigerim Aig

Seems trivial, but I cannot figure it out. Thanks for help.

Answer 1

Just use a simple match

links$source <- match(links$source, friends$name)
links
#   source          target
# 1      1     Andrew John
# 2      1       James Zou
# 3      2         Bz Benz
# 4      2 Yousef AL-alawi
# 5      2  Sherhan Asimov
# 6      2     Aigerim Aig

Answer 2

Something like this?

links$source <- vapply(links$source, function(x) which(friends$name == x), integer(1))

Full example

links <- data.frame(source = c("John", "John", "Alice"), target = c("Jimmy", "Al", "Chris"))
links$source <- vapply(links$source, function(x) which(friends$name == x), integer(1))
links$source
[1] 3 3 2