# 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