## int octal number format

If an integer literal starts with a zero and has at least two digits, it is considered to be in the octal number format.

The number 0 is treated as zero in decimal number format, and 00 is treated as zero in octal number format.

The following line of code assigns a decimal value of 17 (021 in octal) to num1:

// 021 is in octal number format, not in decimal
int num1 = 021;

The following two lines of code have the same effect of assigning a value of 17 to the variable num1:

int num1 = 17; // No leading zero - decimal number format
int num2 = 021; // Leading zero - octal number format. 021 in octal is the same as 17 in decimal

## Demo

public class Main {
public static void main(**String**[] args) {
// No leading zero - decimal number format
int num1 = 17;
// Leading zero - octal number format. 021 in octal is the same as 17 in decimal
int num2 = 021;
**System**.out.println(num1);/*from www.jav a 2 s . c om*/
**System**.out.println(num2);
}
}

## Result

zero in decimal number format and zero in octal number format

int num1 = 0; // Assigns zero to num1, 0 is in the decimal number format
int num2 = 00; // Assigns zero to num1, 00 is in the octal number format

## Demo

public class Main {
public static void main(**String**[] args) {
int num1 = 0; // Assigns zero to num1, 0 is in the decimal number format
int num2 = 00; // Assigns zero to num1, 00 is in the octal number format
**System**.out.println(num1);/*from w w w .jav a2 s. c om*/
**System**.out.println(num2);
}
}

## Result