How is it possible that an octal literal can be negative?

Question

Why nin

const int n = -0123;

octal literal? I thought that all octal literals should start with 0, and this does not happen, since it starts with a negative.

This is a small point that I know, but it causes me a lot of confusion!

Answer 1

How is it possible that an octal literal can be negative?

There are no negative whole literals, only positive ones. The literal here is 0123, which starts with 0 and therefore is octal. -there is a unary minus operator in this expression.

Answer 2

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Answer 3

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When writing an octal, -0123you say that you interpret it as an octal value in the same way 0xFFliterally interprets it as hexadecimal. A sign -is simply a way of applying the unary negation operator to a number 0123.