Java Classes and Objects
What is a Class in Java?
- A class is a blueprint or template for creating objects.
- It defines properties (variables) and behaviors (methods) that the objects created from it will have.
- Objects are the real-world entities created based on a class.
Example
class Car {
// Properties (Fields)
String brand;
int year;
// Behavior (Method)
void displayInfo() {
System.out.println(brand + " - " + year);
}
}
- Car is a class.
- brand and year are fields (variables).
displayInfo()
is a method (behavior).
Real Life Example
Real World | In Java |
---|---|
"Car" is a category | class Car {} |
"BMW", "Tesla" are individual cars | Car bmw = new Car(); Car tesla = new Car(); |
Why do we need Classes?
- To organize code neatly.
- To model real-world things in programming.
- To allow Object-Oriented Programming (OOP) features like:
- Inheritance
- Polymorphism
- Encapsulation
- Abstraction