Generics make your code more flexible and easier to read, and they help you avoid ClassCastExceptions at runtime. Get started with this introduction to using generics with the Java Collections ...

In the HashMap vs. Hashtable debate there is one clear winner. If you are confronted with a choice between the two Java maps, the HashMap is the right collection class to use.

Use Java assertions to test your assumptions about program correctness and check them in your code.