why is not (123 == 0123) in java?

Question

I am developing an application in Android using Eclipse. I wrote the following code and in tests the first and third \"if\" block is not reachable. Why?

Answer 1

Any integer Number Leading With Zero is octal Number (base 8).

0123 is octal Number and 123 is Decimal Number

 0123 = (3*8^0) +(2*8^1)+(1*8^2)+(0*8^4)
        =3+16+64+0
        =83