A Simple Way to Learn Generics

What are Generics?

Generics is a mechanism offered by the Common Language Runtime (CLR) and programming languages that provide one form of code re-use and algorithm re-use.

Advantages of Generics

• Type Safe
• Better Performance

Let us see how we can implement Generics in our code.

I’ve created a class MyGenericSample which has a method ShowMessage that takes two parameters of which one is a Known Type string argument and another being a generic type mentioned as T. Remember defining it in <> before you use.

public void ShowMessage<T>(string msg, T value) //Passed two arguments where msg is Known Type and value as Generic Type
{
   Console.WriteLine("{0}: {1}", msg, value);
}

I’ve overloaded ShowMessage method with three parameters of which one is a Known Type string argument and another two being generic types mentioned as Type1 and Type2.

public void ShowMessage<Type1, Type2>(string msg, Type1 firstParameter, Type2 secondParameter) //Passed three arguments where msg is Known Type and Type1, Type2 as Generic Types
{
   Console.WriteLine("{0}: {1} {2}", msg, firstParameter, secondParameter);
}

Now let’s see how they behave when they are called.

static void Main(string[] args)
{
    MyGenericSample sample = new MyGenericSample();
    sample.ShowMessage < int > ("My Pincode", 500068); //Note: Declare the type of value we are going to send as Generic Type in <>
    sample.ShowMessage < string > ("My City", "Hyderabad");
    sample.ShowMessage < char > ("Gender", 'M');
    //Calling a Generic Method With Various Parameter Types
    sample.ShowMessage < string, string > ("Full Name", "Sridhar", "Sharma");
    Console.ReadLine();
}

Complete code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace GenericsSample
{
    public class MyGenericSample
    {
        public void ShowMessage < T > (string msg, T value) //Passed two arguments where msg is Known Type and value as Generic Type
            {
                Console.WriteLine("{0}: {1}", msg, value);
            }
        public void ShowMessage < Type1, Type2 > (string msg, Type1 firstParameter, Type2 secondParameter) //Passed three arguments where msg is Known Type and Type1, Type2 as Generic Types
            {
                Console.WriteLine("{0}: {1} {2}", msg, firstParameter, secondParameter);
            }
    }
    class Program
    {
        static void Main(string[] args)
        {
            MyGenericSample sample = new MyGenericSample();
            sample.ShowMessage < int > ("My Pincode", 500068); //Note: Declare the type of value we are going to send as Generic Type in <>
            sample.ShowMessage < string > ("My City", "Hyderabad");
            sample.ShowMessage < char > ("Gender", 'M');
            //Calling a Generic Method With Various Parameter Types
            sample.ShowMessage < string, string > ("Full Name", "Sridhar", "Sharma");
            Console.ReadLine();
        }
    }
}

Output



Conclusion

Generics makes the life of developers easy, since they offer Type Safe and there is a performance increase compared with non-generic types.