[jswizzy]

Android development is a mess. Much of the documentation and resources you will find will be outdated. Last time I looked at the code labs from Google many where already deprecated. The Udacity courses are more current than the offical documentation. I'd recommend Programming Kotlin https://pragprog.com/book/vskotlin/programming-kotlin by Venkat Subramaniam if you don't know Kotlin. It's honestly a bad time to learn Android as the ecosystem is in flux with Jetpack and Kotlin and Android X changing everything up.