Java 10

What Java 10 added to Java, with a definition and an example for each feature.

📄️var (local type inference)

`var` lets the compiler work out the type of a local variable from the value on the right, so you do not repeat a long type name.

Java 10 added `List.copyOf`, `Set.copyOf` and `Map.copyOf` to make an immutable copy of an existing collection.