Singleton Design Pattern

The Singleton design pattern is a creational pattern that ensures a class has only one instance and provides a global point of access to that instance. This pattern is useful when you want to control the number of instances created to prevent resource wastage or to ensure consistency in data across the application.

Detailed Explanation of Singleton Pattern in C#

1. Private Constructor

The Singleton class has a private constructor, preventing any other class from creating instances of it directly. This ensures that the Singleton instance can only be accessed through specific methods defined within the Singleton class itself.

public class Singleton
{
    // Private constructor to prevent instantiation
    private Singleton()
    {
        // Initialization code, if any
    }

    // Singleton instance variable
    private static Singleton instance;

    // ...
}

2. Static Instance Variable

The Singleton pattern typically uses a private static variable to hold the single instance of the class. This variable is often lazily initialized, meaning the instance is created only when it's first accessed.

private static Singleton instance;