Tutorial by Examples

class TrivialClass {} A class consists at a minimum of the class keyword, a name, and a body, which might be empty. You instantiate a class with the new operator. TrivialClass tc = new TrivialClass();

With this class: class ObjectMemberVsStaticMember { static int staticCounter = 0; int memberCounter = 0; void increment() { staticCounter ++; memberCounter++; } } the following code snippet: final ObjectMemberVsStaticMember o1 = new ObjectMemberVsStati...

Sometimes the same functionality has to be written for different kinds of inputs. At that time, one can use the same method name with a different set of parameters. Each different set of parameters is known as a method signature. As seen per the example, a single method can have multiple signatures....

Objects come in their own class, so a simple example would be a car (detailed explanations below): public class Car { //Variables describing the characteristics of an individual car, varies per object private int milesPerGallon; private String name; private String color; ...

Constructors are special methods named after the class and without a return type, and are used to construct objects. Constructors, like methods, can take input parameters. Constructors are used to initialize objects. Abstract classes can have constructors also. public class Hello{ // construct...

To initialize a static final fields that require using more than a single expression, a static initializer can be used to assign the value. The following example initializes a unmodifiable set of Strings: public class MyClass { public static final Set<String> WORDS; static {...

Method Overriding and Overloading are two forms of polymorphism supported by Java. Method Overloading Method overloading (also known as static Polymorphism) is a way you can have two (or more) methods (functions) with same name in a single class. Yes its as simple as that. public class Shape{ ...