Dynamic polymorphism is also known as late binding and runtime polymorphism. The major example in this chapter is a polymorphic implementation of linear containers. A function with the same name can have different behavior according to the context of its call. Whereas in static polymorphism we overload a function. Here the base class is derived by the other two classes. Objects are often categorized into groups that share similar characteristics. With inheritance and polymorphism, we can achieve code reuse. Theres no intrinsic support for polymorphism in c, but there are design patterns, using function pointers, base class structure casts, etc. Generally, polymorphism occurs when there is a hierarchy of the classes and they are related by the inheritance.
Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Here one form represent original form or original method always resides in base class and multiple forms represents overridden method which resides in derived classes. The compiler requires an area method and it compiles successfully but the right version of the area method is not. What ever beer you get is okay because your request was very generic in a bar you say i want a samuel adams cherry flavored beer. Method overloading is a concept where we use the same method name many times in the same class, but different parameters. Templates lead to generic code, while polymorphism can lead to dynamic code. Polymorphism means many forms, and it occurs when we have many classes that are related to each other by inheritance. Method overloading is an example of static polymorphism. Java supports parametric polymorphism via generics. An introduction to polymorphism in java the term homonym means a word the same as another in sound and spelling but with different meaning.
Inheritance lets us inherit attributes and methods from another class. At run time, objects of a derived class may be treated as objects of a base class in places such as method parameters and collections or arrays. Classes, inheritance and polymorphism can sometimes be somewhat hard to understand. Listing 2 definition of the shape class in c file shape. But if one or both arguments are floatingpoint, the result is floatingpoint. Polymorphism can be handled in implementation files, templates must be in header files or inline but separated header files. You have a cat asian cat, you can call it is a cat or call it is an animal which is an aspect of the polymorphism. Use of virtual function allows the program to decide at runtime which function is to be called based on the type of the object pointed by the pointer. In this example, lets create a function called func which will take an object which we will name obj.
Static polymorphism is also known as early binding and compiletime polymorphism. On your resume records that youre an asian man, while you actually are a vietnamese. Polymorphism is extensively used in implementing inheritance. Foe example, if customer and account are to object in a program, then the customer object may. Run time polymorphism against virtual function in object oriented. A class is called polymorphic if it contains virtual functions. Method overriding means having two or more methods with the same name, same signature but with different implementation.
If you do not exactly get this type of beer you are allowed to complain in chemistry they talk about polymorph materials as an example h 2 0 is polymorph ice, water, and steam. It is also possible to create a function that can take any object, allowing for polymorphism. Polymorphism is a way to address different things in same way. The aim of this article is to demonstrate a simple and easy technique of applying inheritance and polymorphism in c. Inheritance and polymorphism are the most powerful features of object oriented programming languages. Parametric polymorphism through generics within a class declaration, a field name can associate with different types and a method name can associate with different parameter and return types. Polymorphism the ability to substitute objects of matching interfaces for one another at runtime. Polymorphism provides the ability to a class to have multiple implementations with the same name. The class container is an abstract class from which linear containers lists, queues and. In objectoriented programming, we use 3 main concepts. Static typing for example means types are checked based on the source code, not by executing the program. Static or compile time polymorphism which method is to be called is decided at compiletime only. An example of a dynamic check is an array outofbounds error, which. For example, you have a smartphone for communication.
An example is a list which can accept the type of data it contains through generics. Simplest way is to use function with same name, but different parameter type. Encapsulation is a process of wrapping of data and methods in a single unit. Polymorphism is a greek word, meaning one name many forms. An article a blog a news a video an ebook an interview. It has the ability for classes to provide different implementations of methods that are called through the same name. Virtual functions and so, of course, polymorphism have a meaning only in the context of inheritance. If class rectangle is derived from class quadrilateral, then a rectangle object is a more specific version of a quadrilateral object. A somehow derives from type b, or type c implements an interface that represents.
Function overloading is an example of static polymorphism. Polymorphism is a feature of oops that allows the object to behave differently in different conditions. Lecture notes on polymorphism carnegie mellon university. In our volume example, we could add a second function for setting volume with only two parameters, and one with three. Net articles,gridview articles,code examples of asp. Virtual function is an example of dynamic polymorphism.
The most interesting concepts of polymorphism are related to inheritance. Polymorphism uses those methods to perform different tasks. This allows us to perform a single action in different ways. The type elem must be defined before this file is compiled. Polymorphism is a oops concept where one name can have many forms.
One can distinguish between the two usages through the use of context clues. In simple words, we can define polymorphism as the ability of a message to be displayed in more than one form. So, the goal is common that is communication, but their approach is different. People who work as internists, pediatricians surgeons gynecologists neurologists general practitioners, and other specialists have something in common. Real life example of polymorphism, a person at the same time can have different characteristic. An introduction to polymorphism in java college board. In oop, the concept of inheritance provides the idea of reusability. Polymorphism compiletime binding static binding compiletime binding is to associate a functions name with the entry point of the function at compile time. Like a man at the same time is a father, a husband, an employee. Polymorphism explanation with example for example, in the division expression ab the result depends on the arguments being automatically coerced to the widest type. Java07 7 no late binding for static methods when the decision of which definition of a method to use is made at compile time, that is called static binding this decision is made based on the type of the variable naming the object java uses static, not late, binding with private, final, and static methods in the case of private and final methods.
It can be a call, a text message, a picture message, mail, etc. The process of representing one form in multiple forms is known as polymorphism. Combining of state and behavior in a single container is known as encapsulation. In this lecture we will start the transition from c0 to c. Therefore this will be a tutorial where i will touch the areas of classes, pointers, inheritance and polymorphism. Polymorphism a practical example posted by filip ekberg on nov 2008. More than one function with same name, with different signature in a class or in a same scope is. Polymorphism is a greek word that means manyshaped and it has two distinct aspects. Consider the following example where a base class has been derived by other. The compiler binds virtual function at runtime, hence called runtime polymorphism. Listing 3 examples of using the shape class in c file main.