What is inheritance in java

With the use of inheritance the information is made manageable in a hierarchical order. The class which inherits the properties of other is known as subclass derived class, child class and the class whose properties are inherited is known as superclass base class, parent class. Following is the syntax of extends keyword. Following is an example demonstrating Java inheritance. That is why, using the object of the subclass you can access the members of a superclass.

The Superclass reference variable can hold the subclass object, but using that variable you can access only the members of the superclass, so to access the members of both classes it is recommended to always create reference variable to the subclass.

If you consider the above program, you can instantiate the class as given below. Constructors are not members, so they are not inherited by subclasses, but the constructor of the superclass can be invoked from the subclass.

The super keyword is similar to this keyword. Following are the scenarios where the super keyword is used. It is used to differentiate the members of superclass from the members of subclass, if they have same names.

If a class is inheriting the properties of another class. And if the members of the superclass have the names same as the sub class, to differentiate these variables we use super keyword as shown below.

We are invoking display method of both classes and printing the value of the variable num of both classes. Like to add credit card account with its own unique requirement of deposits. Structural approach: Using structural approach you have to change tested piece of deposit code again. So that they will have access to withdraw and deposit functions in account class.

The functions are not required to be implemented individually. This is Inheritance in java. Skip to content. What is Inheritance? Types of Inheritance Here are the different types of inheritance in Java: Single Inheritance: In Single Inheritance one class extends another class one class only. Inheritance In Java Java Inheritance is a mechanism in which one class acquires the property of another class. Report a Bug. Previous Prev. Next Continue.

Home Testing Expand child menu Expand. SAP Expand child menu Expand. In the example below, the Car class subclass inherits the attributes and methods from the Vehicle class superclass :. Try it Yourself ». We set the brand attribute in Vehicle to a protected access modifier. If it was set to private , the Car class would not be able to access it. Tip: Also take a look at the next chapter, Polymorphism , which uses inherited methods to perform different tasks.

If you don't want other classes to inherit from a class, use the final keyword:. If you try to access a final class, Java will generate an error:.