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Count Instances Of The Class Using C#

Introduction
 
In this blog, I am going to explain how to find the number of objects or instances that are created of a class, using C# . Thus, In my blog, I am going to solve this scenario in two ways.
  • Without using the inbuilt functionality in C#
  • Using the inbuilt functionality in C#

In both the cases, we can use the constructor.

Constructor 
 
Constructor is used to initialize an object (instance) of a class and it has the same name as the class name. Constructor is a like a method without any return type.
 
Destructor
 
Destructor in C# is a special method of a class, which will invoke automatically, when an instance of the class is destroyed.
 
Check the following example to find the number of instances created in a class, using C#.
 
Without using Inbuilt functionality in C#
 
Code
 
The following code will help to find the number of instances created in a class, using C#. In this example, we created 4 objects in a test class. Thus, before the execution of a constructor, we need to add static int count = 0. In each object initialization time of a class, the constructor will execute once. Thus, we will get the number of objects created by a class in C#. 
  1. using System;  
  2.    
  3. namespace data  
  4. {  
  5.     public class test  
  6.     {  
  7.         public static int count = 0;  
  8.         public test()  
  9.         {  
  10.             count = count + 1;  
  11.         }  
  12.     }  
  13.    
  14.     public class Program  
  15.     {  
  16.         public static void Main()  
  17.         {  
  18.             test obj1 = new test();  
  19.             test obj2 = new test();  
  20.             test obj3 = new test();  
  21.             test obj4 = new test();  
  22.             Console.WriteLine(data.test.count);  
  23.         }  
  24.     }  
  25. } 
Output 4
 
 
Using Inbuilt functionality in C#
 
Interlocked
 
Interlocked helps in the threaded programs and it provides automatic operations for the variables that are shared by the multiple threads.
 
Code
  1. using System;  
  2. using System.Threading;  
  3.    
  4. namespace data  
  5. {  
  6.     public class test  
  7.     {  
  8.         public static int count = 0;  
  9.         public test()  
  10.         {  
  11.             Interlocked.Increment(ref count);  
  12.         }  
  13.    
  14.         ~test()  
  15.         {  
  16.             Interlocked.Decrement(ref count);  
  17.         }  
  18.     }  
  19.    
  20.     public class Program  
  21.     {  
  22.         public static void Main()  
  23.         {  
  24.             test obj1 = new test();  
  25.             test obj2 = new test();  
  26.             test obj3 = new test();  
  27.             Console.WriteLine(data.test.count);  
  28.         }  
  29.     }  
  30. } 
Output 3
 
 
Reference

Summary

We learned how to find the number of instances created in a class, using C#. I hope this article is useful for all .NET beginners.