C代码：我做错了什么？

Question

我编写了这段代码来获取学生的字母成绩并计算他们的 GPA。 运行程序时，我可以正确获取学生的姓名和科目，但无法显示成绩或 GPA。

示例输入：

Sally
1
A
N

样本输出：

Enter Student Name: Sally
How many subjects: 1
Grades for subject 1: A
Student Name: Sally
Grade: 4.00
Do you want to enter another student? N

这是我试过的代码sn-p。

#include <stdio.h>

int main()
{
    char studentName[20];
    char grade[10];
    int k1;
    int totalSub1,totalGrade;
    float gpa1;
    char ch1;
    do
    {
        //Student Name
            scanf("%s",studentName);
            printf("Enter Student Name: %s\n", studentName);

        //Number of subjects
            scanf("%d",&totalSub1);
            printf("How many subjects: %d\n",totalSub1);

        //Get Grades
            for(k1=0;k1<totalSub1;k1++)
            {
                printf("Grades:\n%c",grade[k1]);
                scanf("%c",&grade[k1]);
            }
        //Find the gade points
            for(k1=0;k1<totalSub1;k1++)
            {
                totalGrade=0;
                switch(grade[k1])
                {
                    case 'A':
                    totalGrade+=4;
                    break;
                case 'B':
                totalGrade+=3;
                break;
                case 'C':
                totalGrade+=2;
                break;
                case 'D':
                totalGrade+=1;
                break;
                case 'F':
                totalGrade+=0;
                break;
            }
        }
        //Calculate GPA
        gpa1=totalGrade/totalSub1;
        //Print Student name with GPA
        printf("Student Name: %s\n",studentName);
        printf("Grade: %.2f\n",gpa1);
            printf("Do you want to enter another student?\n");
            scanf("%c",&ch1);
        }while(ch1=='Y'||ch1=='y');
    getchar();
    return 0;
}

Answer 1

您的代码中有两个问题：

   scanf("%c",&grade[k1]); 
   scanf("%c",&ch1);

应该替换为，

   scanf(" %c",&grade[k1]); //notice the whitespace
   scanf(" %c",&ch1);

这告诉 scanf 忽略空格！阅读它here

您计算 GPA 的代码也应替换为：

   gpa1=totalGrade/(float)totalSub1; 

假设一个人的 GPA 为 2.67，如果您不添加（浮点）字段 gpa1 将存储 2.00！

Answer 2

您的代码存在几个问题。这是您的固定代码。

#include <stdio.h>

int main()
{
    char studentName[20];
    char grade[10];
    int k1;
    int totalSub1,totalGrade;
    float gpa1;
    char ch1;
    do
    {
        //Student Name
        scanf("%s",studentName);
        scanf("%d",&totalSub1);
        //Get Grades
        for(k1=0; k1<totalSub1; k1++)
        {
            //getchar();  //If you not interested to give extra space in scanf
            scanf(" %c",&grade[k1]);   //extra white space needed to discard ENTER from previous scanf

        }
        //Find the gade points
        totalGrade=0;                     //Initialize totalGrade here not in the loop
        for(k1=0; k1<totalSub1; k1++)
        {
            switch(grade[k1])
            {
            case 'A':
                totalGrade+=4;
                break;
            case 'B':
                totalGrade+=3;
                break;
            case 'C':
                totalGrade+=2;
                break;
            case 'D':
                totalGrade+=1;
                break;
            case 'F':
                totalGrade+=0;
                break;
            }
        }
        //getchar();
        scanf(" %c",&ch1);
        printf("Enter Student Name: %s\n", studentName);
        printf("How many subjects: %d\n",totalSub1);
        for(k1=0; k1<totalSub1; k1++)
        {
            printf("Grades for subject %d: %c\n", k1+1, grade[k1]);
        }
        //Calculate GPA
        gpa1=(float)totalGrade/totalSub1;      //If you don't cast to float then gpa1 get result from integer division of totalGrade and totalSub1
        //Print Student name with GPA
        printf("Student Name: %s\n",studentName);
        printf("Grade: %.2f\n",gpa1);
        printf("Do you want to enter another student? %c\n", ch1);
    }
    while(ch1=='Y'||ch1=='y');
    getchar();
    return 0;
}