C++ Exercises: Convert a octal number to binary number

Last update on April 07 2025 12:59:16 (UTC/GMT +8 hours)

77. Octal to Binary Conversion

Write a C++ program to convert an octal number to a binary number.

Visual Presentation:

C++ Exercises: Convert a octal number to binary number

Sample Solution:-

C++ Code :

#include <iostream> // Include input/output stream library
#include <math.h>   // Include math library for mathematical functions
using namespace std; // Use the standard namespace

int main() // Main function where the execution of the program starts
{
    // Array representing binary values for octal digits from 0 to 7
    int octal_numvalues[] = {0, 1, 10, 11, 100, 101, 110, 111};

    // Declare variables for octal, temporary octal, binary number, remainder, and place value
    long octal_num, tempoctal_num, binary_num, place;
    int rem;

    cout << "\n\n Convert any octal number to binary number:\n"; // Display message prompting for octal to binary conversion
    cout << "------------------------------------------------\n"; // Display separator line
    cout << " Input any octal number: "; // Prompt user to input an octal number
    cin >> octal_num; // Read the octal number input by the user

    tempoctal_num = octal_num; // Store the original octal number for reference
    binary_num = 0; // Initialize the binary number
    place = 1; // Initialize the place value for binary conversion

    // Loop to convert octal to binary using array mapping
    while (tempoctal_num != 0)
    {
        rem = (int)(tempoctal_num % 10); // Get the remainder by dividing the octal number by 10
        binary_num = octal_numvalues[rem] * place + binary_num; // Convert octal digit to its binary equivalent and add to the result
        tempoctal_num /= 10; // Remove the processed digit from the octal number
        place *= 1000; // Increment the place value for the next binary digit position
    }

    cout << " The equivalent binary number: " << binary_num << "\n"; // Display the equivalent binary number
}

Sample Output:

 Convert any octal number to binary number:                            
------------------------------------------------                       
 Input any octal number: 17                                            
 The equivalent binary number: 1111

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program to convert an octal number to its binary representation by first converting to decimal then to binary.
Write a C++ program that reads an octal number and outputs its binary equivalent by mapping each octal digit to a 3-bit binary string.
Write a C++ program to compute the binary representation of an octal input using conversion tables for each digit.
Write a C++ program that converts an octal number to binary by processing each digit and concatenating its binary form.

C++ Code Editor:

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