switch后面括號里面的表達式語句只能是整型或者字符型，而score=score/10屬于算術表達式

#include <stdio.h>
int main()
{
??? int score = 87; //考試分數為87分
??? score=score/10;
??? switch(score)
??? {
??????? /*想想以下代碼為什么用這種方式；
????????? 這種方式的好處？*/
??????? case 10:
??????? case 9:
??????????? printf("等級A");
??????????? break;
??????? case 8:
??????????? printf("等級B");
??????????? break;??????????????? //這里是不是缺點什么？???????????
??????? case 7:
??????? case 6:
??????????? printf("等級C");
??????????? break;??????????????? //這里是不是缺點什么？?
??????? default:
??????????? printf("等級D");
??????????? break;???
??? }
??? return 0;
}

你要單獨寫一行score=score/10;

switch后面那個括號里它幫你寫好了，不用改