After reading Hidden Features of C# I wondered, What are some of the hidden features of Java?
Good Answer: 👌👌👌
Double Brace Initialization took me by surprise a few months ago when I first discovered it, never heard of it before.
ThreadLocals are typically not so widely known as a way to store per-thread state.
Since JDK 1.5 Java has had extremely well implemented and robust concurrency tools beyond just locks, they live in java.util.concurrent and a specifically interesting example is the java.util.concurrent.atomic subpackage that contains thread-safe primitives that implement the compare-and-swap operation and can map to actual native hardware-supported versions of these operations.
Read More: 👉 https://stackoverflow.com/questions/15496/hidden-features-of-java