Clarification about “int” number that begins with 0

Question

public class Test {

    public static void main(String[] args) {
        int i = 012;
        System.out.println(i);
    }
}

Why the output is : <

Answer 1

Octal Number : Any number start with 0 is considered as an octal number (012) i.e. base-8 number system

Simple octal number evaluation :

1*8^1 + 2*8^0 = 10

Octal Number

For More information about Number System