习题6-1 分类统计字符个数

void StringCount(char s[])
{
    int letter, blank, digit, other;
    
    letter = 0;
    blank = 0;
    digit = 0;
    other = 0;
    
    int i = 0;
    while (s[i] != '')        //字符串都是''结尾的 
    {
        if ((s[i] >= 'A' && s[i] <= 'Z') || (s[i] >= 'a' && s[i] <= 'z'))
        {
            letter++;
        }
        else if (s[i] == ' ' || s[i] == '
')
        {
            blank++;
        }
        else if (s[i] >= '0' && s[i] <= '9')
        {
            digit++;
        }
        else
        {
            other++;
        }
        
        i++;
    }
        
    printf("letter = %d, blank = %d, digit = %d, other = %d
", letter, blank, digit, other);
}