Inheritance

Java Inheritance

Inheritance bulletin points

• Creating new classes from already existing classes is called Inheritance.
• Advantage is newly deriving classes will get the all public features from existing classes.
• Newly deriving classes are called sub/child class.
• Existing classes are called as super/parent class.
• java.lang.Object class is the super class for every predefined and user defined classes.
• Without inheritance we can write even single Hello World program also.
• private data of super class can not be inherit to sub class.
• extends keyword is used to inherit the variables and methods from Parent class to child class.
• One class can extends only one class at a time, because Java does not support multiple inheritance

Syntax

           class Parent

           {

                  Assuming that Parent class holding 10 public features;

           }

           class Child extends Parent

           {

                  Assuming that Child class holding 5 public features;

                  So finally Child class having 15 public features including Parent features;

           }

• Assuming that classes A extends B, B extends C, C extends D, here creating object for D class is good, because D class is holding all the features of super classes.
• If we create an object to parent class then we can access only parent class data but not child class data.
• If we create an object to child class then we can get both parent and child classes data.

Thanks for your time.

Nireekshan