Lessons

Let's talk about education. About what it really is. And also about what, contrary to what most people think, it is not. Most people primarily associate education with universities, which they enter after high school. They believe that a good education received at a decent and respected...

If an object exists, it means that somebody needs it... In Java, this is how it works after an object is created, it exists (lives) as long as at least one variable is storing its address (there is at least one reference to it). If there are no more references, the object dies. The garbage collector comes for it and... Actually, everything isn't so tragic as it sounds. Quite the contrary.

Let's dig into "static". Methods can be static and non-static. Ordinary methods are called on an object and have access to its data. Static methods don't have this access: They simply don't have an object reference. They are able to access a class's static variables and other static methods. The details are in the lesson.

Variables, methods, and even classes can be static. You'll learn what this is about and why you need it in higher levels, but for now you can look at the example and ponder what's going on here. We'll use a public static cast as a guinea pig. Sounds intriguing, doesn't it?

The topics we're raising here are laying solid groundwork for the future. It may not be entirely clear why everything is arranged this way, but it's already clear enough to practice doing tasks. We'll examine static methods as we create them in tasks. By the way, have you noticed that the main() method is also totally static?

"Hey, young recruit, who makes a bunch of mistakes every day, even in the simplest programs!" "Um... Hi, Diego. Boy, you really know how to cheer people up!" "Of course, I do! Learn how to say what needs to be said. Like I said, 'every day'. Putting it more politely, my greeting means...

"Hi, Amigo! Let's continue to talk about mistakes. This time, we'll explore mistakes that the compiler will not always help you with. Pay attention and you'll learn something about yourself." "I'm ready to listen, Diego. I hope this won't be too embarrassing for me...

In this level, we have taken a few more steps forward in learning Java. We explored class loading and talked about static variables, methods, and classes. We figured out the most common reasons why the compiler yells at you, as well as the situations where you need to be especially careful to avoid...

Before tackling the last batch of tasks in not just this level, but in the entire first quest, you deserve a good rest! Then you’ll be ready to finish all that remains. But be prepared to have your nerves jangled by this video. It’s a thriller about going completely crazy for Java, based on a novel by Stephen King. :)