Description

Convert the given decimal number into an equivalent octal number means
convert the number with base value 10 to base value 8.

C/C++

/* C Program to convert Decimal to Octal */
//Save it as ConvertDecimalToOctal.c

#include<stdio.h>
int main(){

    int dec, rem, octalNum=0, count=1;

    printf("Enter a decimal number : ");
    scanf("%d", &dec);

    //Storing the decimal value to temporary variable
    int temp = dec;

    while(dec != 0) {

        //Calculation of remainder
        rem = dec % 8;

        //Calculation of octal value
        octalNum += (rem * count);

        // storing exponential value
        count *= 10;

        dec /= 8;
    }

    //Restoring the decimal value
    dec = temp;

    printf("The Octal value of %d is %d", dec, octalNum);

    return 0;
}

Input:
Enter a decimal number : 19

Output:
The octal of 19 is 23

Java

/* Java Program to convert Decimal to Octal */
//Save it as ConvertDecimalToOctal.java

import java.io.*;
import java.util.Scanner;

public class ConvertDecimalToOctal {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        
        System.out.println("Enter a decimal number : ");
        int dec = scanner.nextInt();
        
                //Storing the decimal value to temporary variable
        int temp = dec;
        
        int rem, octalNum=0, count=1;
        
        while(dec != 0) {
            
                        //Calculation of remainder
            rem = dec % 8;
            
                        //Calculation of octal value
            octalNum += (rem * count);
            
                        // storing exponential value
            count *= 10;
            
            dec /= 8;
        }
        
                //Restoring the decimal value
        dec = temp;
        
        System.out.println("The octal of " + dec + " is "+ octalNum);
        
        
        /* 
            There is predefined function in Java to convert decimal to octal
            Integer.toOctalString(decimalNumber)
        */
        
    }
}

Input:
Enter a decimal number : 
19

Output:
The octal of 19 is 23

Related Programs

1) Program to convert Binary to Decimal
2) Program to convert Binary to Hexa Decimal
3) Program to convert Decimal to Binary
4) Program to convert Octal to Decimal
5) Program to find sum of digits of a number
6) Program to reverse a number
7) Program to calculate Factorial of a Number
8) Program to display multiplication table of a number
9) Program to Display Fibonacci Series
10) Program to Display Fibonacci Series using Recursion
11) Program of Simple Calculator using switch
12) Program to print all Squares of numbers from 1 to given Range
13) Program to find sum of first and last digit of a number