Introduction Polymorphism refers to an objects ability to take on different forms. In Java, it is a simple, yet fundamental concept of objected oriented programming. In order to understand polymorphism, it is important to have a solid grasp of inheritance and interfaces in Java. What is polymorphism? A class is considered to be polymorphic…

Introduction Access modifiers in Java are keywords that are used to specify the accessibility of fields, methods, constructors and classes. There are four access modifiers, each specifying a certain level of accessibility: public: can be accessed from anywhere 2. protected: can be accessed from within the class itself, the package and…

Read this to ace every interview question regarding interfaces. What are interfaces? An interface is a reference type similar to a class but different in a sense that it can only contain abstract methods, default methods, static methods, (only default and static methods in interfaces can have a method body)…

Introduction Packages in Java correspond with the directory structure in your project. They are used to group and control accessibility of related classes, interfaces and sub-packages. Why use packages? The advantages of using packages are: Better access control: Packages equip the developer with better access control. Avoid name conflicts: Using packages prevents you from…

In Java, a class can be derived from an existing class and when that happens, the derived class inherits the fields and the methods from that existing class. In Java, and many other languages, this is called inheritance. The class that is derived from an existing class is often referred…

Before we begin discussing the toString method, it is important to have a basic understanding of the class hierarchy in Java. All classes in Java inherit from the Object class; the Object class is at the root of the class hierarchy in Java.

In Java, as is the case with most programming languages, strings are immutable; once a string is initialized with a value, it cannot be changed. StringBuilder What is it and when should I use it? Take a look at the following code for instance:

Static and final keywords in Java are at the core of the language and it is important to have an in-depth understanding of their function. static variables If you’ve every written a Java program of any scale, you’ve come across the “static” keyword. Your first program probably looked something like this:

In this short article, I am going to introduce and implement the binary tree data structure. I will also answer questions such as “What is a full binary tree and what is a complete binary tree?”and “How do I traverse a binary tree?”. First, let’s cover the basic definition of…