The document provides an introduction to Java's fundamental concepts of classes and objects, highlighting their roles in object-oriented programming. A class serves as a blueprint for creating objects, which are instances with defined state and behavior. Understanding these concepts, along with access modifiers and examples, is essential for effective Java programming.

1. JAVA CLASSES AND
OBJECT

2. Introduction
 Java is an object-oriented
programming language.
 Classes and objects are
fundamental concepts in Java.

3. Class definition
 Class head class name_of_class.
 Class body {
data members;
member functions;
};

4. Example
public class Car {
// Fields (variables)
String color;
String model;
int year;

5. What is a Class?
 A class is a blueprint for creating
objects.
 It defines a datatype by bundling data
and methods that operate on the data
into a single unit.

6. Introduction to objects
 Object is an abstraction of real world entity.
 Objects are the variables/instances of classes.
 Syntax for declaring objects is as follows :
Person person = new Person("Alice", 30);

7. What is an Object?
 An object is an instance of a
class.
 It has state (fields) and behavior
(methods).

8. Characteristics of objects:
 It can have its own copy of data members.
 The scope of an object is determined by the
place in which the object is defined.
 It can be passed to a function like normal
variables.
 The members of the class can accessed by
the object using the object to member access
operator or dot operator(.).

9. Access Modifiers
 public: Accessible from anywhere.
 private: Accessible only within the class.
 protected: Accessible within the same package
and subclasses.
 default (no modifier): Accessible within the
same package.

10. Example:
public class Dog {
String name;
void bark() {
System.out.println(name + " says Woof!");
}
}

11. Example:
public class Main {
public static void main(String[] args) {
// Declare and create an object of the Dog class
Dog myDog = new Dog();
// Set the name field
myDog.name = "Buddy";
// Call the bark method
myDog.bark();
}
}

12. Conclusion
 Classes and objects are core components of
Java's object-oriented programming.
 Mastering these concepts is crucial for
effective Java programming.