Skip to main content

inheritance in java



  • Inheritance allows a software developer to derive a new class from an existing one
  • The existing class is called the parent class, or super class, or base class
  • The derived class is called the child class or subclass.
  • As the name implies, the child inherits characteristics of the parent
  • That is, the child class inherits the methods and data defined for the parent class
  • To tailor a derived class, the programmer can add new variables or methods, or can modify the inherited ones
  • Software reuse is at the heart of inheritance
  • By using existing software components to create new ones, we capitalize on all the effort that went into the design, implementation, and testing of the existing software
  • Inheritance relationships often are shown graphically in a UML class diagram, with an arrow with an open arrowhead pointing to the parent class




Examples 
ex 1 

ex 2


Comments

Post a Comment

Popular posts from this blog

Generalization and Specialization

Generalization creates a concept with a broader scope. Specialization creates a concept with a narrower scope. Reusing the interface!  Inheritance: get the interface from the general class. Objects related by inheritance are all of the same type.
Post a Comment
Read more

Aggregation and Decomposition

Idea: make new objects by combining existing objects. Reusing the implementation!  An aggregation consists of a number of (sub-)concepts which collectively is considered a new concept. A decomposition splits a single concept into a number of (sub-)concepts.
Post a Comment
Read more

The Class Concept

A class is a collection of objects (or values) and a corresponding set of methods.  A class encapsulates the data representation and makes data access possible at a higher level of abstraction. Example 1: A set of vehicles with operations for starting, stopping, driving, get km/liter, etc. Example 2: A time interval, start time, end time, duration, overlapping intervals, etc. Example 3: A string, upper case, compare, lower case, etc.  str.equals(otherStr) – class/Java style   strcmp(str, otherStr) – C style
Post a Comment
Read more