1. program to display hello world on the output screen

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            System.Console.WriteLine("Hello World!");
        }
    }
}

2. program to input an integer (or number) and display its value

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            System.Console.WriteLine("Enter a number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Number you entred is "+a);
           
        }
    }
}

3. // program to input two numbers or integers and display their values

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a,b;
            System.Console.WriteLine("Enter first number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter second number");
            b = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("First Number you entred is "+a);
            System.Console.WriteLine("Second Number you entred is " + b);
            
        }
    }
}

4. // program to input three numbers and display their values

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a,b,c;
            System.Console.WriteLine("Enter first number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter second number");
            b = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter third number");
            c = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("First Number you entred is "+a);
            System.Console.WriteLine("Second Number you entred is " + b);
            System.Console.WriteLine("Third Number you entred is " + c);
            
            
        }
    }
}

5. // program to input two numbers and find their sum

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a,b,c;
            System.Console.WriteLine("Enter first number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter second number");
            b = Convert.ToInt32(Console.ReadLine());
            c = a + b;
            System.Console.WriteLine("Sum of two numbers is "+c);
                    
        }
    }
}

6. //program to input three numbers and find sum of three numbers

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a,b,c,d;
            System.Console.WriteLine("Enter first number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter second number");
            b = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter third number");
            c = Convert.ToInt32(Console.ReadLine());
            d = a + b + c;
            System.Console.WriteLine("Sum of three numbers is "+d);
                    
        }
    }
}

7. //program to input two numbers and find the difference between them

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a,b,c;
            System.Console.WriteLine("Enter first number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter second number");
            b = Convert.ToInt32(Console.ReadLine());
            c = a - b;
            System.Console.WriteLine("Difference between two numbers is "+c);
                  
        }
    }
}

8. //program to input two numbers and find their product

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a,b,c;
            System.Console.WriteLine("Enter first number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter second number");
            b = Convert.ToInt32(Console.ReadLine());
            c = a * b;
            System.Console.WriteLine("Product of two numbers is "+c);
         
        }
    }
}

9. // program to input two numbers and display their quotient (division)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a,b,c;
            System.Console.WriteLine("Enter first number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter second number");
            b = Convert.ToInt32(Console.ReadLine());
            c = a / b;
            System.Console.WriteLine("Quotient of two numbers is "+c);
            
        }
    }
}

10. //program to input two numbers and find their remainder (division)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a,b,c;
            System.Console.WriteLine("Enter first number");
            a = Convert.ToInt32(Console.ReadLine());
            System.Console.WriteLine("Enter second number");
            b = Convert.ToInt32(Console.ReadLine());
            c = a % b;
            System.Console.WriteLine("Remainder of two numbers is "+c);
            Console.ReadLine();
        }
    }
}

11. //program to enter a character and display its value

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            char ch;
            ch = 'a';
            Console.WriteLine("Character you entered is " + ch);
            Console.ReadLine();
        }
    }
}

12. //program to input a double value (number with decimal point)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double a;
            Console.WriteLine("Enter a decimal point number");
            a = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Decimal number you entered is " + a);
            Console.ReadLine();
        }
    }
}

13. //program to add two decimal point values

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double a,b,c;
            Console.WriteLine("Enter first decimal point number");
            a = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter second decimal point number");
            b = Convert.ToDouble(Console.ReadLine());
            c = a + b;
            Console.WriteLine("Sum of two decimal numbers is " + c);
            Console.ReadLine();
        }
    }
}

14. //program to input two decimal point numbers and display difference between them

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double a,b,c;
            Console.WriteLine("Enter first decimal point number");
            a = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter second decimal point number");
            b = Convert.ToDouble(Console.ReadLine());
            c = a - b;
            Console.WriteLine("Difference between two decimal numbers is " + c);
            Console.ReadLine();
        }
    }
}

15. //program to input two float (decimal point) values and find their product

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double a,b,c;
            Console.WriteLine("Enter first decimal point number");
            a = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter second decimal point number");
            b = Convert.ToDouble(Console.ReadLine());
            c = a * b;
            Console.WriteLine("Product of two decimal numbers is " + c);
            Console.ReadLine();
        }
    }
}

16. //program to input two double (decimal point ) values and find their division

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double a,b,c;
            Console.WriteLine("Enter first decimal point number");
            a = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter second decimal point number");
            b = Convert.ToDouble(Console.ReadLine());
            c = a / b;
            Console.WriteLine("Quotient of two decimal numbers is " + c);
            Console.ReadLine();
        }
    }
}

17. //program to input principal, rate of interest and time and compute simple interest

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double p,r,t,si;
            Console.WriteLine("Enter prinicpal amount");
            p = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter rate of interest");
            r = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter time in years");
            t = Convert.ToDouble(Console.ReadLine());
            si = (p * r * t) / 100;
            Console.WriteLine("Simple Interest is " + si);
            Console.ReadLine();
        }
    }
}

18. //program to input length and breadth of rectangle and find area of rectangle

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int l, b, area;
            Console.WriteLine("Enter length of rectangle");
            l = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter breadth of rectangle");
            b = Convert.ToInt32(Console.ReadLine());
            area = l * b;
            Console.WriteLine("Area of rectangle is " + area);
            Console.ReadLine();
        }
    }
}

19. //program to input length and breadth of rectangle and compute perimeter of rectangle

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int l, b, perimeter;
            Console.WriteLine("Enter length of rectangle");
            l = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter breadth of rectangle");
            b = Convert.ToInt32(Console.ReadLine());
            perimeter = 2 * (l + b);
            Console.WriteLine("Perimeter of rectangle is " + perimeter);
            Console.ReadLine();
        }
    }
}

20. //program to input side of square and compute area of square

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int side, area;
            Console.WriteLine("Enter side of square");
            side = Convert.ToInt32(Console.ReadLine());
            area = side * side;
            Console.WriteLine("Area of square is " + area);
            Console.ReadLine();
        }
    }
}

21. //program to input base and height of right angled triangle and find area of right angled triangle

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double b,h,area;
            Console.WriteLine("Enter base of right angled triangle");
            b = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter height of right angled triangle");
            h = Convert.ToDouble(Console.ReadLine());
            area = 0.5 * b * h;
            Console.WriteLine("Area of right angled triangle is " + area);
            Console.ReadLine();
        }
    }
}

22. //program to input radius of circle and find area of circle

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double r,area;
            Console.WriteLine("Enter radius of circle");
            r = Convert.ToDouble(Console.ReadLine());
            area = 3.14 * r * r;
            Console.WriteLine("Area of circle is " + area);
            Console.ReadLine();
        }
    }
}

23. //program to input radius of circle and find circumference of circle

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double r,circumference;
            Console.WriteLine("Enter radius of circle");
            r = Convert.ToDouble(Console.ReadLine());
            circumference = 2*3.14 * r;
            Console.WriteLine("Circumference of circle is " + circumference);
            Console.ReadLine();
        }
    }
}

24. //program to demonstrate increment(++) operator , i++ is same as i=i+1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            Console.WriteLine("Enter a number");
            a = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Number you entered is " + a);
            a++;
            Console.WriteLine("Number after applying Increment operator (++) is " + a);
            Console.ReadLine();
        }
    }
}

25. //program to demonstrate deccrement(--) operator , i-- is same as i=i-1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            Console.WriteLine("Enter a number");
            a = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Number you entered is " + a);
            a--;
            Console.WriteLine("Number after applying Decrement operator (--) is " + a);
            Console.ReadLine();
        }
    }
}

26. //program to assign value 10 to a, initializing variable a

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            a = 10;
            Console.WriteLine("Value of a is " + a);
            Console.ReadLine();
        }
    }
}

27. //program to demonstrate (+=) operator, a+=2 is same as a=a+2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            Console.WriteLine("Enter a number");
            a = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Number you entered is " + a);
            a+=2;
            Console.WriteLine("Number after applying += operator is " + a);
            Console.ReadLine();
        }
    }
}

28. //program to demonstrate (-=) operator, a-=2 is same as a=a-2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            Console.WriteLine("Enter a number");
            a = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Number you entered is " + a);
            a-=2;
            Console.WriteLine("Number after applying -= operator is " + a);
            Console.ReadLine();
        }
    }
}

29. //program to demonstrate (*=) operator, a*=2 is same as a=a*2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            Console.WriteLine("Enter a number");
            a = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Number you entered is " + a);
            a*=2;
            Console.WriteLine("Number after applying *= operator is " + a);
            Console.ReadLine();
        }
    }
}

30. //program to demonstrate (/=) operator, a/=2 is same as a=a/2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            Console.WriteLine("Enter a number");
            a = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Number you entered is " + a);
            a/=2;
            Console.WriteLine("Number after applying /= operator is " + a);
            Console.ReadLine();
        }
    }
}

31. //program to demonstrate (%=) operator, a%=2 is same as a=a%2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            Console.WriteLine("Enter a number");
            a = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Number you entered is " + a);
            a%=2;
            Console.WriteLine("Number after applying %= operator is " + a);
            Console.ReadLine();
        }
    }
}

32. //program to input price of an item from user and calculate discount as 10 percent on the price

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double amount, discount;
            Console.WriteLine("Enter Amount");
            amount = Convert.ToDouble(Console.ReadLine());
            discount = 0.1 * amount;
            Console.WriteLine("10% Discount is " + discount);
            Console.ReadLine();
        }
    }
}

33. //program to find volume of box based on width,depth and height

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            double w, d, h, vol;
            Console.WriteLine("Enter Width of box");
            w = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter depth of box");
            d = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter height of box");
            h = Convert.ToDouble(Console.ReadLine());
            vol = w * d * h;
            Console.WriteLine("Volume of box is " + vol);
            Console.ReadLine();
        }
    }
}

34. //program to demonstrate ternary operator or conditional operator, displays 'p' if marks>=40 else displays 'f'

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            char result;
            int marks;
            Console.WriteLine("Enter marks ");
            marks = Convert.ToInt32(Console.ReadLine());
            result = (marks >= 40 ? 'p' : 'f');
            Console.WriteLine("Result is " + result);
            Console.ReadLine();
        }
    }
}

35. //program to demonstrate const keyword to create a constant

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            const double pi=3.14;
            double area;
            area = pi * 10 * 10;
            Console.WriteLine("Area of circle with radius 10 is " + area);
            Console.ReadLine();
        }
    }
}

36. //program to enter a boolean and display its value

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            bool a = true;
            Console.WriteLine("Value of a is " + a);
            Console.ReadLine();
        }
    }
}