Check if a number is positive or negative in C# :

In this C# tutorial, we will learn how to check if a number is positive, negative or zero. The program will ask the user to enter a number. It will check if it is positive, negative or zero and finally print out the result.

With this tutorial, you will learn how to compare a number using if-else condition, how to take user input and how to write a message to the user.

C# program :

using System;
namespace dotnet_sample
{
    class Program
    {
        static void Main(string[] args)
        {
            //1
            int n;
            //2
            Console.WriteLine("Enter a number : ");
            //3
            n = int.Parse(Console.ReadLine());
            //4
            if(n == 0)
            {
                Console.WriteLine(n + " is zero.");
            }
            else if(n > 0)
            {
                //5
                Console.WriteLine(n + " is a positive number.");
            }
            else
            {
                //6
                Console.WriteLine(n + " is a negative number.");
            }
        }
    }
}

Explanation :

The commented numbers in the above program denote the step numbers below :

1. Create one integer n to read the user input.

2. Ask the user to enter a number.

3. Read the number and store it in_ ‘n’._

4. Check if the value of_ ‘n’_ is 0 or not. If yes, print out that it is zero.

5. Else check if it is greater than 0 or not. If yes, print out that it is a positive number.

6. Else print that it is a negative number.

Sample Output :

Enter a number :
0
0 is zero.

Enter a number :
-23
-23 is a negative number.

Enter a number :
45
45 is a positive number.

This program is available on Github