c - Why is !0 equal to 1 and not -1? -

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the following code

printf("!%d = %d\n", 0, !0); printf("!%d = %d\n", 1, !1); printf("!%d = %d\n", -1, !-1);

gives

!0 = 1 !1 = 0 !-1 = 0

now, considering 0 = 0x00000000, shouldn't !0 = 0xffffffff = -1 (for signed representation)? messes using int / long in bitfield , inverting @ once.

what reason behind this? avoid !1 considered boolean true?

the reason in standard c, has been specified operators returning boolean return either 1 or 0. !0 calculates logical not of 0, i.e. 1. logical not of 1 0.

what want use bitwise not operator, i.e. ~0 should 0xffffffff == -1.


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