ipof.sh

#!/bin/bash

# Googooli bash function for resolve a hostname to the first IP address or find your public ip address
# Example:
# $ ipof www.google.com
#   216.58.204.132
# find your public ip address when nothing is sent
# $ ipof
#   x.x.x.x

function ipof() {
	if [ -z "$1" ]
	then
		curl ipinfo.io/ip
	else
		dig +short $1 | awk '{ print ; exit }'
	fi
}

Update:

• find your public ip address when nothing is sent, changes, Thanks to @smmtaheri