Back to: C#.NET Programs and Algorithms

**Octal to Binary Conversion in C# with Examples**

In this article, I am going to discuss **Octal to Binary Conversion in C#** with Examples. Please read our previous article, where we discussed **Hexadecimal to Octal Conversion in C#**. At the end of this article, you will understand, what are Octal and Binary Number Systems are and how to convert an Octal Number into its equivalent Binary Number using C#.

**What is Octal Number System?**

The octal numeral system or oct is the base-8 number system and uses the digits 0 to 7. Octal numerals can be made from binary numerals by grouping consecutive binary digits into groups of three (starting from the right). Example: (5303)_{8}

**What is Binary Number System?**

The binary numeral system uses the number 2 as its base (radix). As a base-2 numeral system, it consists of only two numbers 0 and 1. The binary number system is the way to represent the number in computer architecture. Example: (101101)_{2}

**Logic to Convert Octal to Binary in C# **

To find the conversion of octal to decimal number simply we need to follow the below steps

- First, we take the octal number.
- Then we convert it as a decimal equivalent.
- We convert the decimal number into their binary equivalent.
- Then we store the number and we get the required binary number.

**Example: Convert to octal number (56)**_{8} into binary

_{8}into binary

Solution:

Given octal number is (56)8

The equivalent binary number of 5 is: 101

The equivalent binary number of 6 is: 110

Equivalent binary number of (56)_{8} is (101110)_{2}

For better understanding, please have a look at the below diagram which shows how to convert (56)_{8} into a binary number.

**Example: Octal to Binary Number Conversion in C# **

The following C# Program will convert an Octal number to its equivalent Binary number.

using System; class OctalToBinary { static void Main() { string octalNumber = "170"; System.Console.WriteLine("Octal Number is: " + octalNumber); int i = 0; string binary = ""; while (i < octalNumber.Length) { char c = octalNumber[i]; switch (c) { case '0': binary += "000"; break; case '1': binary += "001"; break; case '2': binary += "010"; break; case '3': binary += "011"; break; case '4': binary += "100"; break; case '5': binary += "101"; break; case '6': binary += "110"; break; case '7': binary += "111"; break; default: System.Console.WriteLine("\nInvalid Octal Digit " + octalNumber[i]); break; } i++; } System.Console.WriteLine("Bianry value is: " + binary); Console.ReadKey(); } }

**Output:**

**Example: Taking input from the user**

In the following C# program, we will take the octal number from the user and then convert the octal number to its equivalent binary number and print it on the console.

using System; public class OctalToBinary { public static void Main() { long n1, n2, k = 1; long decimal_number = 0, i = 1, j, d; long binary_number = 0; Console.Write("Input an octal number (using digit 0 - 7) : "); n1 = Convert.ToInt32(Console.ReadLine()); n2 = n1; for (j = n1; j > 0; j /= 10) { d = j % 10; if (i == 1) k *= 1; else k *= 8; decimal_number = decimal_number + (d * k); i++; } i = 1; for (j = decimal_number; j > 0; j /= 2) { binary_number = binary_number + (decimal_number % 2) * i; i *= 10; decimal_number /= 2; } Console.Write("\nThe Octal Number: {0}\nThe equivalent Binary Number: {1} \n\n", n2, binary_number); Console.ReadKey(); } }

**Output:**

**C# Code (Using function) **

In the below example, we have created one method to convert the octal number to its equivalent binary number.

using System; class OctalToBinary { static string octalToBinary(string octalNumber) { int i = 0; string binary = ""; while (i < octalNumber.Length) { char c = octalNumber[i]; switch (c) { case '0': binary += "000"; break; case '1': binary += "001"; break; case '2': binary += "010"; break; case '3': binary += "011"; break; case '4': binary += "100"; break; case '5': binary += "101"; break; case '6': binary += "110"; break; case '7': binary += "111"; break; default: System.Console.WriteLine("\nInvalid Octal Digit " + octalNumber[i]); break; } i++; } return binary; } static void Main() { Console.Write("Input an octal number (using digit 0 - 7) : "); string octalNumber = Console.ReadLine(); Console.WriteLine("Octal Number is : " + octalNumber); System.Console.WriteLine("Bianry value is: " + octalToBinary(octalNumber)); Console.ReadKey(); } }

**Output:**

In the next article, I am going to discuss **how to Convert Octal to Decimal numbers in C#** with Examples. Here, in this article, I try to explain **how to convert an octal number to its equivalent binary number in C**# with Examples and I hope you enjoy this Octal to Binary Conversion in C# article.