Need help setting up a static ip on my Raspberry Pi 3

https://raspberrypi.stackexchange.com/questions/37920/how-do-i-set-up-networking-wifi-static-ip-address/74428#74428

But consider this...

Typically you only need a static ip address in a server application. This all works well in a home network where you have a router and access to the router settings. It becomes more difficult on a public network.