C# All members of a static class are static. Why?

In object-oriented programming, a static class is a class in which all members (fields, methods, properties) are marked as static. This means that they belong to the class itself rather than to instances of the class (objects). Here are the reasons why all members of a static class are static:

1. Consistency: Making all members static in a static class ensures consistency and clarity in the design. It clearly indicates that the class is meant to hold shared data or functionality that is not tied to any specific instance.

2. No Instance Dependencies: Static members can be accessed without creating an instance of the class. This is important for a static class, as it doesn't make sense to have instance-specific members in a class that cannot be instantiated.

3. Shared Data/Functionality: The primary purpose of a static class is to provide a container for shared data or functionality that applies to the class as a whole rather than individual instances. All instances of the class share the same static members.

4. Efficiency: Static members are loaded into memory only once, regardless of how many instances of the class are created. This can lead to more efficient memory usage and performance gains.

5. Prevent Instance Modification: By making all members static, you prevent accidental modification of instance-specific data or calling instance-specific methods, reinforcing the idea that this class is not meant to be instantiated.

Here's an example of a static class in C#:

public static class Utility
{
    // Static field
    private static int count;

    // Static method
    public static void IncrementCount()
    {
        count++;
    }

    // Static property
    public static int Count
    {
        get { return count; }
    }
}

In this example, both the field count and the methods IncrementCount and Count are marked as static, as they are intended to be shared across all instances of the Utility class.