Printing declared char value in C

Question

I understand that character variable holds from (signed)-128 to 127 and (unsigned)0 to 255

char x;
x = 128;

printf(\"%d\\n\", x); 

But how doe

Answer 1

Lets look at the binary representation of 128 when stored into 8 bits:

1000 0000

And now let's look at the binary representation of -128 when stored into 8 bits:

1000 0000

The standard for char with your current setup looks to be a signed char (note this isn't in the c standard, look here if you don't believe me) and thus when you're assigning the value of 128 to x you're assigning it the value 1000 0000 and thus when you compile and print it out it's printing out the signed value of that binary representation (meaning -128).

It turns out my environment is the same in assuming char is actually signed char. As expected if I cast x to be an unsigned char then I get the expected output of 128:

#include 
#include 

int main() {
  char x;
  x = 128;
  printf("%d %d\n", x, (unsigned char)x);
  return 0;
}

gives me the output of -128 128

Hope this helps!