c - unsigned char i 是否等同于 unsigned j？

Question

在下面的程序中，我使用了 unsigned 关键字。

#include <stdio.h>

int main()
{
        unsigned char i = 'A';
        unsigned j = 'B';
        printf(" i = %c j = %c", i, j);
}

输出:

 i = A j = B

unsigned char i是否等同于unsigned j？

Answer 1

Is unsigned char i equivalent to unsigned j?

否，当省略类型说明符且任何 signed、unsigned、short 或 long使用说明符，假定为 int。

这意味着下面的声明是等价的:

long a;
long int a;

unsigned short b;
unsigned short int b;

char 的符号性问题在于，当省略 signed 或 unsigned 时，符号性取决于实现:

char x; // signedness depends on the implementation
unsigned char y; // definitely unsigned
signed char z; // definitely signed