A Simple Calculator Class in C# 6

This article is based on the original article that was previously written using older version of Visual Studio. You can find the original article on the given below link:

• A Simple Calculator Class
  

This article shows how to create a new class and call its member functions from Main program. Calculator is a class which has some member functions such as square, add, subtract, multiply, division etc.

ClassLibrary:

• We can create a class library (in other words DLL file) of code containing classes and methods.
  
  
• One DLL file can be used in many applications in .NET like Console Application, Windows Application and Web Application and so on.
  
  
• To use a DLL file in an application we need to add a reference to the DLL file.
  
  
• DLL is not a self-executable file instead it is to be shared by many applications for code reusability purposes.

Procedure to Create a Class Library:

• Start a new project in Visual Studio from the New Project dialogue box, select Class Library Template from the Project Template Window.
  
  
• In the Name box, type a name for your Class Library. Then click OK.
  
  
• When you click OK, it will create a namespace with the name we gave for the Library and you will see the following in the code window:
  

  using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Threading.Tasks;
  
  namespace ClassLibrary1
  {
      public class CalCulator {}
  }

See the file Class1.cs in the Solution Explorer as given below:


Now add the following methods to the Calculator to do arithmetic operations (Square, Addition, Subtraction, Multiplication and Division).

We've added five simple methods; one for Square, second for addition, third for subtraction, fourth for multiplication, and fifth for Division. Similarly, we can add more methods to CalCulator for other operations.

public class CalCulator
{
    // Square function
    public int Square(intnum)
    {
        returnnum * num;
    }
    // Add two integers and returns the sum
    public int Add(int num1, int num2)
    {
        return num1 + num2;
    }

    // Multiply two integers and retuns the result
    public int Multiply(int num1, int num2)
    {
        return num1 * num2;
    }
    // Subtracts small number from big number
    public int Subtract(int num1, int num2)
    {
            if (num1 > num2)
            {
                return num1 - num2;
            }

            return num2 - num1;

        }
        //performing Division on two float variables.
    public float Division(float num1, float num2)
    {
        return num1 / num2;
    }

}

This shows how to use CalCulator class from Main C# program:

using ClassLibrary1;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            {
                CalCulator sq = new CalCulator();
                Console.WriteLine(sq.Square(12));
                Console.WriteLine(sq.Add(8, 63));
                Console.WriteLine(sq.Multiply(5, 8));
                Console.WriteLine(sq.Subtract(10, 42));
                Console.WriteLine(sq.Division(3, 4));
                Console.ReadLine();
            }
        }
    }
}

Output:



To read other articles on the Calculator, please click on the following references link:

• Class Library Creation in .NET
  
• C# Calculator