Here's how to make classes, fields, methods, constructors, and objects work together in your Java programs.

This post explains how to use classes in Java to build objects and organize your code. Also learn: constructors, static methods, and more!

Object-oriented systems are usually partitioned into layers of related responsibilities and only dependencies in one direction are allowed, from higher layers (more specific, less reusable) to lower ...

Why does Java's standard class library contain empty interfaces like Cloneable and Serializable? Find out why in this sixth installment in the "Object-oriented language basics" series. You'll also ...

What is a Java string? A Java string is a sequence of characters that exists as an object of the class java.lang. Java strings are created and manipulated through the string class. Once created, a ...

The IComparable interface lets you create objects that know how to sort themselves correctly. This interface also provides an example of a high-level strategy for building and extending your classes.

While designing the class structure, you might find that some classes share functionality with other classes. In that case, you can extend classes by creating subclasses to prevent duplication of ...