# Java convert decimal to octal

Let’s learn java convert decimal to octal.

## Java program for decimal to octal conversion

Write program to convert given decimal number to equivalent octal number is one of the frequently asked interview question.

In the below java program we need to convert given decimal number (base value 10) into octal number (base value 8).

To represent numeric value, decimal number system uses 0-9 digits and octal number system uses 0-7 digits.

There are two ways,

• using Integer.toOctalString() method.
• with our own logic.

public static String toOctalString(int i)

toOctalString method returns a the string representation of the unsigned integer value represented by the argument in octal (base 8).

```import java.util.Scanner;

public class DecimalToOctal
{
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
int number = sc.nextInt();
String strOctal = Integer.toOctalString(number);
System.out.println("To octal: " + strOctal);
sc.close();
}
}

```

Output:

To octal: 217

Before going with our own logic first let’s see algorithm to convert decimal to octal.

1. User enters a number.
2. Then find remainder of given number with 8.
3. Now store the remainder.
4. Divide number by 8.
5. Repeat until number is not equal to zero.
6. Finally reverse the number.
```public class DecimalToOctalDemo
{
static void toOctal(int number)
{
// octalNumber array stores octal number
int[] octalNumber = new int;
// here's the counter for octalNumber array
int a = 0;
while(number != 0)
{
// store remainder in octal array
octalNumber[a] = number % 8;
number = number / 8;
a++;
}
// print octal number array in reverse order
for(int b = a - 1; b >= 0; b--)
{
System.out.print(octalNumber[b]);
}
}

public static void main(String[] args)
{
int num = 65;
toOctal(num);
}
}

```

Output:

101