Operators

In C#, you can use the following types of operators:

Arithmetic operators

v  The commonly used arithmetic operators are:

+     Used to add two numbers.

-      Used to subtract two numbers.

*     Used to multiply two numbers.

/      Used to divide one number by another.

%    Used to divide two numbers and return the remainder.

Example

using System;

namespace Arithmetic_Operators

{

    class Program

    {

        static void Main(string[] args)

        {

            int num1, num2;

            int add, sub, mul;

            float div;

            //Accepting Values from users

            Console.Write("Enter first number\t\t");

            num1 = Convert.ToInt32(Console.ReadLine());

            Console.Write("\n\nEnter second number\t\t");

            num2 = Convert.ToInt32(Console.ReadLine());

            //Processing Values

            //Used + operator for adding values

            add = num1 + num2;

            //Used - operator for subtracting values

            sub = num1 - num2;

            //Used * operator for multiplying values

            mul = num1 * num2;

            //Used / operator for dividing values

            div = (float)num1 / num2;

            //Displaying Output

            Console.WriteLine("\n\n=====================\n");

            Console.WriteLine("Addition\t\t{0}", add);

            Console.WriteLine("Subtraction\t\t{0}", sub);

            Console.WriteLine("Multiplication\t\t{0}", mul);

            Console.WriteLine("Division\t\t{0}", div);

            Console.WriteLine("\n=======================\n");

            Console.ReadLine();

        }

    }

}

Arithmetic assignment operators

v  The commonly used arithmetic assignment operators are:

+=   For example: X+=Y; can also be interpreted as X = X + Y;.

-=    For example: X-=Y; can be interpreted as X = X – Y;.

*=   For example: X*=Y; can be interpreted as X = X * Y;.

/=   For example: X/=Y; can be interpreted as X = X / Y;.

%=  For example: X%=Y; can be interpreted as X = X % Y;.

Example

using System;
 
namespace assignment_operator
{
  class Program
   {
     static void Main(string[] args)
      {
        int num1,num2;
 
        num1 = 10;
        num2 = 5;
 
        num1 += num2; // same as num1=num1+num2
        Console.WriteLine("Add = {0}", num1);
 
        num1 -= num2; // same as num1=num1-num2
        Console.WriteLine("\n\nSubtraction = {0}", num1);
 
        num1 *= num2; // same as num1=num1*num2
        Console.WriteLine("\n\nMultiplication={0}",num1);
 
        num1 %= num2; // same as num1=num1%num2
        Console.WriteLine("\n\nModulus = {0}", num1);
 
        Console.ReadLine();
      }
   }
}

Unary operators

v  The commonly used increment and decrement operators are:

++(Pre/Post increment operator): Used to increment the value of an operand by 1, pre or post assignment.

--(Pre/Post decrement operator): Used to decrement the value of an operand by 1, pre or post assignment.

Example

using System;
 
namespace Increment_Operator
{
  class Program
   {
     static void Main(string[] args)
      {
        int i = 0; // initialization
 
        i++; // i incremented by one. It is post increment
 
        Console.WriteLine("The value of i is {0}", i);
 
        Console.ReadLine();
      }
   }
}

Comparison operators

v  Some commonly used comparison operators are:

< : Used to check whether expression1 is less than expression2.

> : Used to check whether expression1 is greater than expression2.

<= : Used to check whether expression1 is less than or equal to expression2.

>= : Used to check whether expression1 is greater than or equal to expression2.

== : Used to check whether expression1 is equal to expression2.

!= : Used to check whether expression1 is not equal to expression2.

Example

using System;
 
namespace Comparison_Operator
{
  class Program
   {
     static void Main(string[] args)
      {
        int num1, num2;
 
        //Accepting two inputs from the user
        Console.Write("Enter first number\t");
        num1 = Convert.ToInt32(Console.ReadLine());
        Console.Write("Enter second number\t");
        num2 = Convert.ToInt32(Console.ReadLine());
 
        //Processing comparison
        //Check whether num1 is greater than or not
        if (num1 > num2)
         {
           Console.WriteLine("{0} is greater than {1}", num1, num2);
         }
        //Check whether num2 is greater than or not
        else if (num2 > num1)
         {
           Console.WriteLine("{0} is greater than {1}",num2, num1);
         }
        else
         {
           Console.WriteLine("{0} and {1} are equal",num1, num2);
         } 
        Console.ReadLine();          
      }
   }
}

Logical operators

v  Some commonly used logical operators are:

&& : Returns true if both, expression1 and expression2, are true.

! : Returns true if the expression is false.

|| : Returns true if either expression1 or expression2 or both of them are true.

^ : Returns true if either expression1 or expression2 is true. It returns false if both expression1 and expression2 are true or if both expression1 and expression2 are false.

Example

using System;

namespace Or_operator

{

    class Program

    {

        static void Main(string[] args)

        {

            string uname, pwd;

        label: //Creating label

            Console.Write("\n\nEnter your login name:\t");

            uname = Console.ReadLine();

            Console.Write("Enter your password:\t");

            pwd = Console.ReadLine();

            if ((uname=="Kumar" || uname=="Amit")&&(pwd=="Kumaramit"))

            {

                Console.WriteLine("\nLogin Successful.");

            }

            else

            {

               Console.WriteLine("\nUnauthorised Access.Aborting...");

            }

            Console.Write("\n\nPress Y or y for continue.:\t");

            char ans = Convert.ToChar(Console.ReadLine());

            if (ans=='Y' || ans=='y')

            {

                goto label; //goto label

            }

            Console.WriteLine("Press  Enter for Aborting...");

            Console.ReadLine();

        }

    }

}