How to get the last parameter in shell [duplicate]

Question

I'm wondering how to obtain the last argument passed to a bash function, like this:

#!/bin/bash

function hello() {
    all=$@         # all arguments
    n=$#           # number of arguments
    first_arg=$1   # argument one
    last_arg= ???  # How to get the last argument?
}

How to set $last_arg to the value of the last argument passed to the function?

Answer 1

If all holds the $@, then the last argument is ${all[*]: -1}