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


java convert octal to decimal

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

Also read – octal to binary in java

However, if the String does not contain a parsable int, NumberFormatException is thrown.

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

Also read – java program to convert hexadecimal to decimal

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:

java convert octal to decimal

Octal to decimal converter

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

Octal base 8 Decimal base 10
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 7
10 8
11 9
12 10
13 11
14 12
15 13
16 14
17 15
20 16
30 24
40 32
50 40
60 48
70 56
100 64

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 – decimal to binary in java

Click here to learn vice versa of above java program.

Also read – hexadecimal to decimal in java

Also read – octal to hexadecimal in java