Classes & Objects (Part 4)

1. Java Classes

Java is an object-oriented programming language.

Everything in Java is associated with classes and objects, along with its attributes and methods. For example: in real life, a car is an object. The car has attributes, such as weight and color, and methods, such as drive and brake.

A Class is like an object constructor, or a "blueprint" for creating objects.

To create a class, use the keyword class:

A class can contain any of the following variable types.

• ▪ Local variables − The variable will be declared and initialized within the method and the variable will be destroyed when the method has completed.

• ▪ Instance variables − Instance variables are variables within a class but outside any method. These variables are initialized when the class is instantiated. 

• ▪ Class variables − Class variables are variables declared within a class, outside any method, with the static keyword.

2. Java Objects 

In Java Object is created from Classes. An Object is any Real life entity , Eg:- Car , Dog , Machine , etc.

We can create object by the following code:

  public class MyClass {   
   public static void main(String args[]) {   
   MyClass obj = new MyClass(); //create an object named obj   
  }   
  } 

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