Question

Character values between 0 and 255 can be denoted by octal literals from "\000" to "\377".

So shouldn’t "\400" be a compile-time error? Eclipse does not complain, however… what’s going on here?

Answer 1

It’s interpreting it as “\40” + “0”

The Java Language Specification describes this here.

OctalEscape:
    \ OctalDigit
    \ OctalDigit OctalDigit
    \ ZeroToThree OctalDigit OctalDigit

OctalDigit: one of
    0 1 2 3 4 5 6 7

ZeroToThree: one of
    0 1 2 3