Java_class,Object

• Java is an object-oriented programming language.
• Everything revolves around class and object.

What is a Class in Java?

• To create a class, use the keyword class.
• A class is a user-defined data type in Java that groups variables and methods together into a single unit.
• A class acts as a blueprint that describes how objects should look and behave.

class Student {
    String name;
    int age;
    void study() {
        System.out.println(name + " is studying");
    }
}
Here:
name,age → variables
study() → method
Student → class

What is an Object in Java?

• In Java, an object is created from a class.
• An object is a real-world entity created from a class that contains actual data and can use the methods defined in the class.
• An instance of a class means an object created from that class.

Why “Instance” is Important?

• It represents the class in memory.
• Multiple instances can be created from one class.
• Each instance can store different values.

public class Main {
    public static void main(String[] args) {
        Student s1 = new Student();
        s1.name = "Ajay";
        s1.age = 21;
        s1.study();
    }
}