#include <stdio.h>
void main()
{float score;
char grade;
printf("请输入学生成绩：");
scanf("%f",&score);
while(score>100|| score<0);
{printf("\n 输入有误，请重新输入");
scanf("%f",&score);
}
switch((int)(score/10)
{
case 10:
case 9: grade="A";break;
case 8: grade="B";break;
case 7: grade="C";break;
case 6: grade="D";break;
case 5: grade="E";break;
case 4: grade="E";break;
case 3: grade="E";break;
case 2: grade="E";break;
case 1: grade="E";break;
}
printf("成绩是%5.1f,相应的等级是%c。\n",score,grade);
}

switch((int)(score/10))这里少个括号

还是出错
--------------------Configuration: fdsaf - Win32 Debug--------------------
Compiling...
fsdaf.cpp
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(14) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(15) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(16) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(17) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(18) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(19) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(20) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(21) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
C:\Program Files\Microsoft Visual Studio\MyProjects\fdsaf\fsdaf.cpp(22) : error C2440: '=' : cannot convert from 'char [2]' to 'char'
        This conversion requires a reinterpret_cast, a C-style cast or function-style cast
执行 cl.exe 时出错.

fsdaf.obj - 1 error(s), 0 warning(s)

char grade;
grade='A';break; 你声明的是字符，而不是字符串

那该怎么改了··

改好了


#include <stdio.h>
void main()
{float score;
char grade;
printf("请输入学生成绩:");
scanf("%f",&score);
if(score>100||score<0)
{printf("\n 输入有误，请重新输入");
scanf("%f",&score);
}
switch((int)(score/10))
{
case 10:
case 9: grade='A';break;
case 8: grade='B';break;
case 7: grade='C';break;
case 6: grade='D';break;
case 5: grade='E';break;
case 4: grade='E';break;
case 3: grade='E';break;
case 2: grade='E';break;
case 1: grade='E';break;
}
printf("成绩是%5.1f,相应的等级是%c。\n",score,grade);
}

while那行不用分号的

还有我觉得双引号改不改都可以

噢
试过了
双引号要改哈

谢谢了