Java Exercises: Convert a octal number to a binary number

Java Basic: Exercise-26 with Solution

Write a Java program to convert a octal number to a binary number.

Octal number: The octal numeral system is the base-8 number system, and uses the digits 0 to 7.

Binary number: A binary number is a number expressed in the base-2 numeral system or binary numeral system. This system uses only two symbols: typically 1 (one) and 0 (zero).

Test Data:
Input any octal number: 7

Pictorial Presentation: Octal to Binary number

Sample Solution:

Java Code:

import java.util.Scanner;

public class Exercise26 {
public static void main(String[] args) 
 {
  Scanner in = new Scanner(System.in);
  int[] octal_numvalues = {0, 1, 10, 11, 100, 101, 110, 111};
  long octal_num, tempoctal_num, binary_num, place;
  int rem;
  System.out.print("Input any octal number: ");
  octal_num = in.nextLong();
  tempoctal_num = octal_num;
  binary_num = 0;
  place = 1;
  while (tempoctal_num != 0)
  {
   rem = (int)(tempoctal_num % 10);
   binary_num = octal_numvalues[rem] * place + binary_num;
   tempoctal_num /= 10;
   place *= 1000;
  }
  System.out.print("Equivalent binary number: " + binary_num+"\n");
 }
}

Sample Output:

Input any octal number: 7                                                                                    
Equivalent binary number: 111

Flowchart:

Java Code Editor:

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