The function match
works on vectors:
x <- sample(1:10)
x
# [1] 4 5 9 3 8 1 6 10 7 2
match(c(4,8),x)
# [1] 1 5
match
only returns the first encounter of a match, as you requested. It returns the position in the second argument of the values in the first argument.
For multiple matching, %in%
is the way to go:
x <- sample(1:4,10,replace=TRUE)
x
# [1] 3 4 3 3 2 3 1 1 2 2
which(x %in% c(2,4))
# [1] 2 5 9 10
%in%
returns a logical vector as long as the first argument, with a TRUE
if that value can be found in the second argument and a FALSE
otherwise.