Getting negative value with bit-fields

问题

I have a question related to bit-fields in C. Here I have such a structure:

struct Register
{
  int bit:1;
};

int main(void)
{
  struct Register bit = {1};

  printf("\nbit = %d", bit.bit);
  return 0;
}

Can you please explain me why do I get:

bit = -1

回答1:

If you're working with bitfields, you should use unsigned int. signed int is a problem for bit-fields.

回答2:

use unsigned int , it stores 0 and 1,

struct Register
{
unsigned int bit:1;
};

int main(void)
{
 struct Register bit = {1};

 printf("\nbit = %d", bit.bit);
 return 0;
}

来源：https://stackoverflow.com/questions/30614340/getting-negative-value-with-bit-fields