![ class Doctor
{
void Doctor_Details()
{
System.out.println("Doctor Details...");
}
}
class Surgeon extends Doctor // class Surgeon is a child class of class Doctor
{
void Surgeon_Details()
{
System.out.println("Surgen Detail...");
}
}
public class Hospital
{
Public static void main(String args[])
{
Surgeon s = new Surgeon();
s.Doctor_Details();
s.Surgeon_Details();
}
}
As we know, Surgeon IS A Doctor](https://image.slidesharecdn.com/inheritanceinjava-200401190646/85/Inheritance-in-java-8-320.jpg)
Inheritance in java
- 2. Inheritance is a mechanism in which one class acquires the property of another class. For example, a child inherits the traits of his/her parents. With inheritance, we can reuse the fields and methods of the existing class. Hence, inheritance facilitates Reusability and is an important concept of OOPs.
- 3. Single Inheritance Multiple Inheritance Multilevel Inheritance Hierarchical Inheritance Hybrid Inheritance
- 4. In Single Inheritance one class extends another class (one class only). In Multiple Inheritance, one class extending more than one class. Java does not support multiple inheritance.
- 5. In Multilevel Inheritance, one class can inherit from a derived class. Hence, the derived class becomes the base class for the new class. In Hierarchical Inheritance, one class is inherited by many sub classes. example, Class B, C, and D inherit the same class A.
- 6. Hybrid inheritance is a combination of Single and Multiple inheritance. All the public and protected members of Class A are inherited into Class D, first via Class B and secondly via Class C.
- 7. JAVA INHERITANCE is a mechanism in which one class acquires the property of another class. In Java, when an "Is-A" relationship exists between two classes, we use Inheritance. The parent class is called a super class and the inherited class is called a subclass. The keyword extends is used by the sub class to inherit the features of super class. Java doesn't support hybrid/Multiple inheritance. Inheritance is important since it leads to the reusability of code.
- 8. class Doctor { void Doctor_Details() { System.out.println("Doctor Details..."); } } class Surgeon extends Doctor // class Surgeon is a child class of class Doctor { void Surgeon_Details() { System.out.println("Surgen Detail..."); } } public class Hospital { Public static void main(String args[]) { Surgeon s = new Surgeon(); s.Doctor_Details(); s.Surgeon_Details(); } } As we know, Surgeon IS A Doctor
- 9. The super keyword is similar to "this" keyword. (Keyword THIS is a reference variable in Java that refers to the current object.) The keyword super can be used to access any data member or methods of the parent class. Super keyword can be used at variable, method and constructor level. Syntax: super.<method-name>();
- 10. Reusability - facility to use public methods of base class without rewriting the same. Extensibility - extending the base class logic as per business logic of the derived class. Data hiding - base class can decide to keep some data private so that it cannot be altered by the derived class Overriding -With inheritance, we will be able to override the methods of the base class so that meaningful implementation of the base class method can be designed in the derived class.
- 11. If a method is deleted in the "base class" or aggregate, then we will have to re-factor in case of using that method.Here things can get a bit complicated in case of inheritance because our programs will still compile, but the methods of the subclass will no longer be overriding base class methods. These methods will become independent methods in their own right. Main disadvantage of using inheritance is that the two classes (base and inherited class) get tightly coupled. This means one cannot be used independent of each other.