char *str;
//小写字母转换为大写(方法1)
while(*str >= 'a' && *str <= 'z') //小写字母ascii范围
{
*str = *str - ' '; //大小写字母ascii码值相差32,空格的ascii值为32
str++;
}
//小写字母转换为大写(方法2)
char *p;
p = str;
for(p = str; *p != '\0'; p++)
{
if(*p >= 'a' && *p <= 'z') //小写字母ascii范围
{
*p=*p-32; //ascii相差32
}
}