How to find common elements from multiple vectors?

Question

Can anyone tell me how to find the common elements from multiple vectors?

a <- c(1,3,5,7,9)
b <- c(3,6,8,9,10)
c <- c(2,3,4,5,7,9)

Answer 1

intersect_all <- function(a,b,...){
  all_data <- c(a,b,...)
  require(plyr)
  count_data<- length(list(a,b,...))
  freq_dist <- count(all_data)
  intersect_data <- freq_dist[which(freq_dist$freq==count_data),"x"]
  intersect_data
}


intersect_all(a,b,c)

UPDATE EDIT A simpler code

intersect_all <- function(a,b,...){
  Reduce(intersect, list(a,b,...))
}

intersect_all(a,b,c)