Java convert octal to decimal

Let’s learn java convert octal to decimal.

Java convert octal to decimal

To convert octal to decimal use parseInt() method of Integer class. Syntax for Integer.parseInt() method is as follows:

public static int parseInt(String s, int radix) throws NumberFormatException

Integer.parseInt() method returns the integer represented by the string argument in the specified radix.

For example: 141₈ = 1×8² + 4×8¹ + 1×8⁰ = 97

However, if the String does not contain a parsable int, NumberFormatException is thrown. Here’s program to convert octal to decimal.

public class OctalToDecimalDemo
{
   public static void main(String[] args)
   {
      String strOctal = "141";
      // converting octal to decimal number using Integer.parseInt() method
      int decimal = Integer.parseInt(strOctal, 8);
      System.out.println(decimal);
   }
}

Output:

Octal to decimal converter

Here’s table to convert from octal to decimal converter.

Meanwhile let’s see octal to decimal conversion using custom method. Here’s the java program.

public class OctalCode
{
   public static int octalToDecimal(int octalNumber)
   {
      int decimal = 0;
      int num = 0;
      while(true)
      {
         if(octalNumber == 0)
         {
            break;
         }
         else
         {
            int temp = octalNumber % 10;
            decimal += temp * Math.pow(8, num);
            octalNumber = octalNumber / 10;
            num++;
         }
      }
      return decimal;
   }
   public static void main(String[] args)
   {
      System.out.println("141 octal is : " + octalToDecimal(141));
      System.out.println("230 octal is : " + octalToDecimal(230));
      System.out.println("100 octal is : " + octalToDecimal(100));
   }
}

Output:

141 octal is : 97
230 octal is : 152
100 octal is : 64

Also read – garbage collection in java