how to set value of octal in java?

Question

I am trying to write following code.but it gives me error kindly help me.

    int six=06;
    int seven=07;
    int abc=018;
    int nine=011;
    System.out.println("Octal 011 ="+nine);
    System.out.println("octal O18 =" + abc);

why i cant give 018 and 019 to variable.i can give value 020 and 021 to variable. Why this happen? what's the reason behind this Kindly tell me.
I got Following error

            integer number too large: 018
            int eight=018;

Answer 1

Octal is base-8 number system, so it means digit can be from 0 to 7, you can't use digit 8 (and 9 too) in octal number system.