Static vs Singleton Design Patterns in C#: Which to Use When

Category > CSHARP || Published on : Thursday, March 9, 2023 || Views: 138 || C# Design Patterns Static Pattern Singleton Pattern Object-Oriented Programming Software Development


When developing software applications in C#, developers have the option to use static and singleton design patterns. Each approach offers its own advantages and disadvantages depending on the specific use case. In this article, we will explore the differences between static and singleton patterns in C# and provide examples of when to use each.

Introduction :

When developing software applications in C#, there are many ways to create and use objects. Two commonly used approaches are the static and singleton design patterns. Both patterns offer advantages and disadvantages depending on the specific use case. In this article, we will explore the differences between static and singleton patterns in C#, and provide examples of when to use each.

Static Pattern The static pattern allows access to an object or method without creating an instance of the class. This is useful when there is no need to create multiple instances of a class, or when the class requires only one instance for the lifetime of the application. Static members are accessed using the class name, followed by the member name.

Here is an example of a static class in C#:

public static class MathHelper
{
    public static int Add(int num1, int num2)
    {
        return num1 + num2;
    }
}

In this example, the MathHelper class has a single static method Add that takes two integer parameters and returns their sum. The Add method can be accessed without creating an instance of the MathHelper class, by calling MathHelper.Add(5, 3).

Singleton Pattern The singleton pattern is used when there is a need to have only one instance of a class throughout the lifetime of an application. The singleton pattern ensures that only one instance of the class is created and provides a global point of access to that instance.

Here is an example of a singleton class in C#:

public sealed class Logger
{
    private static readonly Lazy<Logger> instance = new Lazy<Logger>(() => new Logger());

    private Logger()
    {
    }

    public static Logger Instance
    {
        get
        {
            return instance.Value;
        }
    }

    public void Log(string message)
    {
        Console.WriteLine(message);
    }
}

In this example, the Logger class is a singleton class with a private constructor, a private static field instance, and a public static property Instance. The instance field is initialized lazily using the Lazy<T> class, which ensures that the instance is created only when it is first accessed. The Instance property provides access to the single instance of the Logger class.

When to Use Static vs Singleton When deciding whether to use a static or singleton pattern in C#, consider the following factors:

  • Number of instances needed: If there is a need for only one instance of a class, use the singleton pattern. If multiple instances of a class are needed, use the static pattern.
  • Lifetime of the object: If the object needs to be available throughout the lifetime of the application, use the singleton pattern. If the object is only needed for a short period of time, use the static pattern.
  • Thread safety: The singleton pattern can be used to ensure thread safety by creating a single instance of a class that is shared across threads. The static pattern does not offer this level of thread safety.

Conclusion

In summary, the static and singleton patterns are both useful design patterns in C#, and offer different benefits depending on the specific use case. The static pattern is used when there is no need to create multiple instances of a class, while the singleton pattern is used when there is a need for only one instance of a class throughout the lifetime of an application. By understanding the differences between these patterns, developers can choose the one that best suits their needs.