What are the different types of inheritance in Java?
In Java, inheritance is a fundamental concept that allows a class to inherit properties and behaviors from another class. This feature is crucial for code reuse and creating a hierarchical structure in object-oriented programming. There are several types of inheritance in Java, each serving a specific purpose and providing unique functionalities. In this article, we will explore the different types of inheritance in Java and understand their significance.
1. Single Inheritance
Single inheritance is the most common form of inheritance in Java, where a class inherits properties and methods from a single superclass. This is achieved by using the `extends` keyword. The subclass inherits all the non-private members of the superclass, including fields, methods, and constructors.
“`java
class Parent {
public void display() {
System.out.println(“Parent class method”);
}
}
class Child extends Parent {
public void show() {
System.out.println(“Child class method”);
}
}
public class Main {
public static void main(String[] args) {
Child obj = new Child();
obj.display(); // Parent class method
obj.show(); // Child class method
}
}
“`
2. Multilevel Inheritance
Multilevel inheritance occurs when a class inherits from a subclass, which in turn inherits from another superclass. This creates a hierarchy of classes, where each subclass inherits properties and behaviors from its parent class.
“`java
class Grandparent {
public void display() {
System.out.println(“Grandparent class method”);
}
}
class Parent extends Grandparent {
public void show() {
System.out.println(“Parent class method”);
}
}
class Child extends Parent {
public void print() {
System.out.println(“Child class method”);
}
}
public class Main {
public static void main(String[] args) {
Child obj = new Child();
obj.display(); // Grandparent class method
obj.show(); // Parent class method
obj.print(); // Child class method
}
}
“`
3. Hierarchical Inheritance
Hierarchical inheritance is a type of inheritance where a single superclass is inherited by multiple subclasses. This creates a branching structure in the inheritance hierarchy.
“`java
class Parent {
public void display() {
System.out.println(“Parent class method”);
}
}
class Child1 extends Parent {
public void show() {
System.out.println(“Child1 class method”);
}
}
class Child2 extends Parent {
public void print() {
System.out.println(“Child2 class method”);
}
}
public class Main {
public static void main(String[] args) {
Child1 obj1 = new Child1();
obj1.display(); // Parent class method
obj1.show(); // Child1 class method
Child2 obj2 = new Child2();
obj2.display(); // Parent class method
obj2.print(); // Child2 class method
}
}
“`
4. Hybrid Inheritance
Hybrid inheritance is a combination of hierarchical and multilevel inheritance. It involves a single superclass that is inherited by multiple subclasses, and these subclasses are further inherited by other subclasses.
“`java
class Parent {
public void display() {
System.out.println(“Parent class method”);
}
}
class Child1 extends Parent {
public void show() {
System.out.println(“Child1 class method”);
}
}
class Child2 extends Parent {
public void print() {
System.out.println(“Child2 class method”);
}
}
class Grandchild extends Child1 {
public void display() {
System.out.println(“Grandchild class method”);
}
}
public class Main {
public static void main(String[] args) {
Grandchild obj = new Grandchild();
obj.display(); // Grandchild class method
obj.show(); // Child1 class method
obj.print(); // Child2 class method
}
}
“`
Conclusion
Understanding the different types of inheritance in Java is essential for creating efficient and reusable code. Single, multilevel, hierarchical, and hybrid inheritance provide various ways to organize and extend classes, allowing developers to leverage the power of object-oriented programming effectively. By choosing the appropriate type of inheritance, one can create a well-structured and maintainable codebase.
