C# Program to Check Odd Number

Posted in C# Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 180 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, dealing with numbers is a fundamental task. One common requirement is checking whether a given number is odd or not.

An odd number is an integer that is not exactly divisible by 2 and leaves a remainder of 1 when divided by 2.

In this tutorial, we will explore a C# program designed to check whether a given number is odd. The program involves using the modulo operator to determine if the number is not divisible by 2.

📄 Example

Let's delve into the C# code that accomplishes this task.

OddNumberChecker.cs

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using System;

class OddNumberChecker {
  // Function to check if a number is odd
  static bool IsOdd(int number) {
    // If the remainder is 1, the number is odd
    return number % 2 != 0;
  }

  // Driver program
  static void Main() {
    // Replace this value with the number you want to check
    int number = 15;

    // Call the function to check if the number is odd
    if (IsOdd(number))
      Console.WriteLine($"{number} is an odd number.");
    else
      Console.WriteLine($"{number} is not an odd number.");
  }
}

💻 Testing the Program

To test the program with different numbers, modify the value of number in the Main method.

Output

15 is an odd number.

🧠 How the Program Works

The program defines a class OddNumberChecker containing a static method IsOdd that takes an integer number as input and returns true if the number is odd, and false otherwise.
Inside the Main method, replace the value of number with the desired number you want to check.
The program calls the IsOdd method and prints the result using Console.WriteLine.

📏 Between the Given Range

Let's take a look at the C# code that checks and displays odd numbers in the specified range.

Program.cs

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using System;

class Program {
  static void Main() {
    // Define the range
    int start = 1;
    int end = 10;

    Console.WriteLine($"Odd Numbers in the range {start} to {end}:");

    // Loop through the range and check for odd numbers
    for (int i = start; i <= end; i++) {
      if (IsOdd(i)) {
        Console.Write($"{i} ");
      }
    }

    Console.WriteLine();
  }

  // Function to check if a number is odd
  static bool IsOdd(int number) {
    return number % 2 != 0;
  }
}

💻 Testing the Program

Output

Odd Numbers in the range 1 to 10:
1 3 5 7 9

The range for this program is fixed from 1 to 10. To test the program, simply compile and run it.

🧠 How the Program Works

The program defines a function IsOdd that checks whether a given number is odd or not.
In the Main method, it specifies the range from 1 to 10 and prints the header indicating the range.
It then iterates through the range and calls the IsOdd function to check for odd numbers.
If a number is odd, it is printed.

🧐 Understanding the Concept of Odd Number

Before delving into the code, let's understand the concept of odd numbers. An odd number is an integer that is not exactly divisible by 2. In other words, when an odd number is divided by 2, the remainder is 1.