r - How does order work?

Question

This is a very embarrassing question, but I cannot understand the result of the following:

> order(c(3,1,2))
[1] 2 3 1

So, it's saying the ordered sequence is 2, 3, 1? How?

Answer 1

> a <- c(30,10,20)     # sample data
> sort(a)              # sort returns your vector sorted
[1] 10 20 33
> order(a)             # order returns the *indices* in the sorted vector
[1] 2 3 1
> a[order(a)]          # so if you select your numbers with those indices
[1] 10 20 30           # you get your vector sorted