#!/bin/bash

echo "Last argument only (works with bash/ksh only): ${@: -1}"
echo "Last argument only (works with bash 3.x+ only): ${!#}"
echo "Last argument only (works with bash 3.x+ only): $BASH_ARGV"
echo "Last argument only (works with bash 3.x+ / ksh only): ${@:$#}"
echo "Last argument only (works with bash 3.x+ only): ${BASH_ARGV[0]}"

echo -n "Last argument only (portable version): "
for i in $@; do :; done
echo "$i"