Understanding Generics in C#

Generics allow you to delay the specification of the data type of programming elements in a class or a method, until it is actually used in the program. In other words, generics allow you to write a class or method that can work with any data type.

When the compiler encounters a constructor for the class or a function call for the method, it generates code to handle the specific data type.

Generics is a technique that enriches your programs in the following ways:

• It helps you to maximize code reuse, type safety, and performance.
• You can create generic collection classes. The .NET Framework class library contains several new generic collection classes in the System.Collections.Genericnamespace. You may use these generic collection classes instead of the collection classes in the System.Collections namespace.
• You can create your own generic interfaces, classes, methods, events, and delegates.
• You may create generic classes constrained to enable access to methods on particular data types.
• You may get information on the types used in a generic data type at run-time by means of reflection.

Simple example on Generics -

// Declare the generic class.

public class GenericList<T>

{

    void Add(T input) 

   {

      //Do something here

   }

}

class TestGenericList

{

    private class ExampleClass 

   { }

   

    static void Main()

    {

        // Declare a list of type int.

        GenericList<int> list1 = new GenericList<int>();

        // Declare a list of type string.

        GenericList<string> list2 = new GenericList<string>();

        // Declare a list of type ExampleClass.

        GenericList<ExampleClass> list3 = new GenericList<ExampleClass>();

    }

}