A class in C sharp declared with static keyword is a C# static class. The static class prevents the object creation and can be used directly without creating any instance of class. A class that is not a static class is used after creating its object with new keyword. But the class that is static is used directly without creating its object.

How to create static class in c#?

In order to create static class in C sharp, you need to put static keyword before the name of the class as follow:

staticclasscalculation
{
}

1. The static class can contain only static members.

2. The static class cannot be instantiated.

3. The static class is a sealed class so you cannot inherit and override its members.

Static Member

A static method, field, property, or event is callable on a class even when no instance of the class has been created. If any instances of the class are created, they cannot be used to access the static member. Only one copy of static fields and events exists, and static methods and properties can only access static fields and static events. Static members are often used to represent data or calculations that do not change in response to object state. 

Example

using System;
namespace StaticKeywordConsoleApplication
{
    static class calculation
    {
        public static int add(int num1, int num2)
        {
            return num1 + num2;
        }
    }
 
    class Program
    {
        static void Main(string[] args)
        {
            int result;
            result = calculation.add(6, 22);
            Console.WriteLine("Addition = " + result);
        }
   }
}

Output:-

Addition = 28

In this example, I’ve created a static class calculation with a static member function add() who add two numbers and return the value. In class Program, add() is called directly with the calculation class name and dot operator, there is no need of object.