Vi Huynh

This is one of the great things about Kotlin, everything in Kotlin is not nullable unless you specifically declare it in this way. The way to do this is with the “?” question mark which also suggest you that the value…

…e you notice that there are no primitive types, we don’t use “double” but “Double”. This is because everything in Kotlin is an object. For performance, the compiler will transform some of these objects to primitive types internally.

…tand the structure of DB, how entities are connected, etc. If you understand it — you can plan your redux store properly (will be mentioned next)