Polymorphism in Object-Oriented Programming(OOPS)
Polymorphism is one of the fundamental concepts of OOP. The word polymorphism means having many forms.
In simple words, we can define polymorphism as the ability of a message to be displayed in more than one form.
Real life example of polymorphism
A person at the same time can have different characteristic. Like a man at the same time is a father, a husband, an employee.
What is Polymorphism?
Polymorphism is a way in which we can define multiple functions in a single name i.e. single name and multiple meaning.
In below example(DP example) we have a we have same method name with different parameters:
void CalculateArea(int side);
void CalculateArea(int l, int b);
void CalculateArea(float radius);
Types of Polymorphism in C#
Polymorphism is of two types. They are:
1. Compile time polymorphism
Compile time polymorphism is method and operators overloading. It is also called early binding. Below is example of method overloading:
class Program
{
public class WebsiteInfo
{
public void display(string name)
{
Console.WriteLine("Website name is :" + name);
}
public void display(int rank, string name)
{
Console.WriteLine("Website name is :" + name);
Console.WriteLine("Ranking of website is : " + rank);
}
}
static void Main(string[] args)
{
WebsiteInfo obj = new WebsiteInfo();
obj.display("DotNat Palace");
obj.display(210000, "dotnetpalace.com");
Console.ReadLine();
}
}
You should keep in mind that overloads must be different in their signature, which means the name and the number and type of parameters.
You should consider overloading a method when you for some reason need a couple of methods that take different parameters, but conceptually do the same thing.
2. Runtime polymorphism
Runtime time polymorphism is done using inheritance and virtual functions. Method overriding is called runtime polymorphism. It is also called late binding.
When overriding a function, you change the behavior of the function for the derived class
Following is the example of implementing a run time polymorphism in C#.
public class Users
{
public virtual void GetUserInfo()
{
Console.WriteLine("Base Class User");
}
}
// Derived Class
public class Details : Users
{
public override void GetUserInfo()
{
Console.WriteLine("Derived Class User");
}
}
class Program
{
static void Main(string[] args)
{
Users d = new Users();
d.GetUserInfo();
Details b = new Details();
b.GetUserInfo();
Console.WriteLine("\nPress Enter Key to Exit..");
Console.ReadLine();
}
}
Summary
To summarise, The polymorphism is the feature of object-oriented programming which indicates single name with multiple meaing. You should use polymorphism for almost same reason you need couple (or more than that) of method that take different parameters (eg. Calculate area of different types of shapes). Hope you picked up a thing or two from this article.
Cheers!