Method Overshadowing in Java

Method Overshadowing is another name given to method overriding.

In Inheritance when a method in a subclass has the same name and type signature as a method in its superclass, then the method in the subclass is said to override the method in the superclass.

 Here the method in the subclass is overshadowing the method in the superclass.

When an overridden method is called from within a subclass, it will always refer to the version of that method defined by the subclass.

If we want to explicitly call the method defined in the superclass then we can use the super keyword.

super.method_name  i.e the method we want to call of superclass.

What is Agile Software Development?

An iterative and incremental (evolutionary) approach performed in a highly collaborative manner with just the right amount of ceremony to produce high quality software in a cost effective and timely manner which meets the changing needs of its stakeholders.

or

Agile software development is a group of software development methodologies based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizing, cross-functional teams.

 

Core principles

–“Fits just right” process

–Continuous testing and validation

–Consistent team collaboration

–Rapid response to change

–Ongoing customer involvement

–Frequent delivery of working software

Agile can mean different things to different people, so it can be helpful to create some common ground to avoid misunderstandings.  As IBM Rational has worked with companies who are undertaking Agile Development, we’ve made some key observations:

Agile software development can be significantly different from one organization to another.  Agile is not a “one size fits all” proposition

Agilists do a lot more testing, in fact they often write a test before they write sufficient production code to fulfill that test, then they iterate

Agilists work very closely together and ideally work closely with their stakeholders

Changing requirements are seen as a competitive advantage, as long as you can act on them, not as something that you need to prevent

Agilists deliver working software every iteration, providing concrete evidence of actual progress on the project.  Daily builds, or even multiple times a day are highly desirable

Shorter iterations are desirable, from as short as one-to-two weeks, 4 weeks as a common recommendation, although up to 8 weeks will occur at scale

Method Overriding in Java

• When a method in a subclass has the same name and type signature as a method in its superclass, then the method in the subclass is said to override the method in the superclass.
•  When an overridden method is called from within a subclass, it will always refer to the version of that method defined by the subclass. The version of the method defined by the superclass will be hidden.
•  Method overriding occurs only when the names and the type signatures of the two methods are identical. If they are not, then the two methods are simply overloaded.

Why Use Method Overriding?

Overridden methods allow Java to support run-time polymorphism.

Polymorphism is essential to object-oriented programming for one reason:

it allows a general class to specify methods that will be common to all of its derivatives, while allowing subclasses to define the specific implementation of some or all of those methods. Overridden methods are another way that Java implements the “one interface, multiple methods” aspect of polymorphism.

 

Dynamic Method Dispatch in Java

• Dynamic method dispatch is the mechanism by which a call to an overridden method is resolved at run time, rather than compile time.
• Dynamic method dispatch is important because this is how Java implements run-time polymorphism.

Super keyword in Java- Java Key Points

In Java super keyword has two main uses

1)The first calls the superclass’ constructor.

2)The second is used to access a member of the superclass that has been hidden by a member of a subclass.

1)The first calls the superclass’ constructor.

super( ) must always be the first statement executed inside a subclass’ constructor.

When a subclass calls super( ), it is calling the constructor of its immediate superclass.

2)The second is used to access a member of the superclass that has been hidden by a member of a subclass.

This second form of super is most applicable to situations in which member names of a subclass hide members by the same name in the superclass.