What is an unsigned char?

Question

In C/C++, what an unsigned char is used for? How is it different from a regular char?

Answer 1

signed char and unsigned char both represent 1byte, but they have different ranges.

   Type        |      range
-------------------------------
signed char    |  -128 to +127
unsigned char  |     0 to 255

In signed char if we consider char letter = 'A', 'A' is represent binary of 65 in ASCII/Unicode, If 65 can be stored, -65 also can be stored. There are no negative binary values in ASCII/Unicode there for no need to worry about negative values.

Example

#include 

int main()
{
    signed char char1 = 255;
    signed char char2 = -128;
    unsigned char char3 = 255;
    unsigned char char4 = -128;

    printf("Signed char(255) : %d\n",char1);
    printf("Unsigned char(255) : %d\n",char3);

    printf("\nSigned char(-128) : %d\n",char2);
    printf("Unsigned char(-128) : %d\n",char4);

    return 0;
}

Output -:

Signed char(255) : -1
Unsigned char(255) : 255

Signed char(-128) : -128
Unsigned char(-128) : 128