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

Get a deep dive into using method references in your Java programs, including stream operations, event listeners, and constructors and factories.

For example, if Java infers a type to be a String, it will not assigned that type to an int or a float later on in the code. int x = 10; x = "ten"; // Error: violation of strong typing in Java When ...