对char类型的值进行算术运算

下面是一个类型为char的算术运算示例：

#include <stdio.h> 

int main(void) 
{ 
    char letter = 'C';                          // letter contains the decimal code value 67
    printf(The character is %c\n, letter);

    letter = letter + 3;                        // letter now contains 70, which is 'F'

    printf(The character is %c\n, letter);
    return 0; 
}