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Java Java Objects (Retired) Meet Objects Creating Classes

Chaz Hall
Chaz Hall
1,970 Points

I'm not comprehending the main structure of java.

I don't know why I'm having a tough time with the concepts of java structure. Source File->Class File->Methods->Statements.

Can anyone ELI5? Maybe use the example of some type of game, in very simple terms?

1 Answer

A proper answer would be quite long. But I'll start with the first part of your question. When you code in Java you write text, usually in some IDE. That text is saved in a .java file. When you compile, the text is translated into byte code and saved in a .class file. When you run your code the JVM converts the byte code into machine language code. The rules are: the .java file must be named the same as the class name. So if you write a public class Student {...} the file must be named Student.java. And when you compile it the byte code file will be named Student.class.

In Java methods must be inside classes. In some languages they are called functions outside classes and methods inside. But in Java they are all methods. You can't have functions (i.e., methods outside classes). Methods take 0 to n parameters as input, and may but do not have to return something. So methods can have parameters and a return type. They also have a code block, which is a set of one or more statements inside curly braces.