Languages Focus: Class..Object

In short, a class is a data type, and an object is an instance of a class type. A class has methods (routines), properties (member variables), and a constructor. The current values of the properties is the current state of the object. The UML is one of the diagraming disciplines that allows you to document the various changing states of a series of objects.

//Declare class.

public class Cyborg {

  //Fields.

  private String cyborgName;

  private int age;

  //Constructor.

  public Person() {

  cyborgName = "unknown";

  age = 0;

  }

}

//Create object from class.

Cyborg p = new Cyborg();

p.getClass(); //From the Object base class.