Question

I want to split a column containing emailaddresses at the “@”.

d$domain<-strsplit( d$email, "@")[[1]]

Does not work. What is the correct way to do this?

Answer 1

(Maybe) more than one line is necessary:

for (i in 1:length(row.names(d)){    
d$domain[i]<-unlist(strsplit( d$email[i], "@"))[2]
}

(Note: d$email must be character and not factor and while you used 1 as the index in your question, the index of 2 will correspond to an email’s domain)

Update: I think there is still a way to complete this task in one line by using ‘apply’ but I’m not sure how to do this … yet.

One line answer (after defining function):
fn <- function(x){unlist(strsplit(x,"@"))[2]}
d$domain <- lapply(d$email, fn)