Why is 08 not a valid integer literal in Java?

Question

Why is 08 considered an out of range int but 07 and below are not?

Answer 1

In Java, if you are defining an int with a leading '0' denotes that you are defining a number in Octal.

int a = 08 is giving out of range error because there is no any number '8' in Octal. Octal provides 0-7 numbers only.

If you define a = 07 then it's not giving out of range error because the numbers '0' and '7' are within the Octal's range.