我刚刚编写了这段代码，我无法让它工作 - 更不用说输出所需的结果了。我应该创建一个程序来计算未知数量的学生的GPA（我已经缩小到最多25个），分别具有未知数量的类（也缩小到最多10个以使我的生活更轻松。）
任何人都可以看到我犯了什么错误，并可能把我推向正确的方向吗？我感谢任何人的时间和建议:)）
// C Program - GPA calculator for x amount of students with x amount of classes
// Program developer: Diana Wright - Novembet 22nd, 2014
#include <stdio.h>
int main(void) {
// Declare variables
int grade[5], g, class_num[9], c;
char name[24], n;
float GPA=0.0, grade_point=0.0, result=0.0;
// Input student names implying amount of students
for(n=0; n<25; n++) {
scanf(" %s", &name[n]);
printf("Please enter student names: %s.", name[n]);
// Input number of classes
for(c=0; c<10; c++) {
scanf(" %d", &class_num[c]);
printf("Please enter amount of classes (max.10): %d", class_num[c]);
// Input grades
for(g=0; g<=class_num; g++) {
scanf(" %d", &grade[g]);
printf("Please enter students' grades: %d.", grade[g]);
}
// Conversion of grades
if (grade == "A"){
grade_point = 4.0;
}
if (grade == "B"){
grade_point = 3.0;
}
if (grade == "C")
{
grade_point =2.0;
}
if (grade == "D"){
grade_point = 1.0;
}
if (grade == "F"){
grade_point = 0.0;
}
// Formula to calculate GPA
result += grade_point[g];
GPA = result/class_num[c];
}
}
// Print user input and results in a table
printf(“\n Student name \t Grades \t GPA”);
for(n=0; n<25; n++) {
printf(“ %s \t %d \t %f”, name[n], grade[g], GPA);
}
return 0;
}
Diana 3 A A A Edward 4 B C B A Stuart 4 A F C D Bert 2 F F
答案 0 :(得分：2)
// the following implements the needed data set,
// corrects several coding errors
// has (not yet run) compiling code
编辑：以下代码已过时，请进一步查看新代码
#include <stdio.h>
#include <string.h>
struct studentGrade
{
char name[24];
char grades[10];
int class_num;
float GPA;
};
int main(void)
{
// Declare variables
struct studentGrade studentGrades[25] = {{"",{'F','F','F','F','F','F','F','F','F','F'},0,0.0F}};
int c; // index into student grades[]
int n; // student number/loop counter
float grade_point=0.0f, result=0.0f;
// Input student names implying amount of students
for(n=0; n< (sizeof( studentGrades)/sizeof(struct studentGrade)); n++)
{
result = 0.0f; // initialize for each student
printf( "please enter student name:\n ");
scanf(" %s", (char*)(studentGrades[n].name) );
printf("Student Name is: %s.", studentGrades[n].name);
printf("please enter student class count:\n");
scanf(" %d", &studentGrades[n].class_num);
printf("Student Number of classes: %d", studentGrades[n].class_num);
// Input class grades
for(c=0; c< 10; c++)
{
printf("please enter grade for class: %d", c);
scanf(" %c", &(studentGrades[n].grades[c]));
printf("student grade for class: %d is %c\n", c, studentGrades[n].grades[c]);
// following makes wild assumption that grade entered
// is 'A'...'F'
// Conversion of grades
grade_point = 0.0f; // init for each class
switch( studentGrades[n].grades[c] )
{
case 'A':
grade_point = 4.0f;
break;
case 'B':
grade_point = 3.0f;
break;
case 'C':
grade_point = 2.0f;
break;
case 'D':
grade_point = 1.0f;
break;
case 'F':
grade_point = 0.0f;
break;
default:
printf( "invalid grade entered\n");
c--; // so will properly handle loop control, etc
break;
} // end switch
result += grade_point;
// Formula to calculate GPA
result += grade_point;
} // end for each grade
studentGrades[n].GPA = result/(float)c;
} // end for each student
// Print user input and results in a table
printf("\n Student name \tGPS\n\t\tgrades\n");
for(n=0; n< (sizeof(studentGrades) / sizeof( struct studentGrade)); n++)
{
if( 0 != strlen(studentGrades[n].name) )
{
printf( " %s \tGPS: %.2f\n",
studentGrades[n].name,
studentGrades[n].GPA);
for( c=0; c< studentGrades[n].class_num; c++)
{
printf("\tclass: %d\t%c:\n", c, studentGrades[n].grades[c] );
}
}
}
return 0;
}
编辑：新代码：
#define语句来消除魔法＆＃39;编号现在是新代码：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_STUDENTS 25
#define MAX_NAME_LEN 23
#define MAX_GRADES 10
#define STR_VALUE(x) STR(x)
#define STR(x) #x
struct studentGrade
{
char name[ MAX_NAME_LEN+1 ];
char grades[ MAX_GRADES ];
int class_num;
float GPA;
};
int main(void)
{
// Declare variables
struct studentGrade studentGrades[ MAX_STUDENTS ] =
{
{"",
{'F','F','F','F','F','F','F','F','F','F'}
,0,
0.0F
}
};
float result = 0.0f;
// Input student names implying amount of students
for( size_t whichStudent=0;
whichStudent < (sizeof( studentGrades)/sizeof(struct studentGrade));
whichStudent++)
{
result = 0.0f; // initialize for each student
printf( "please enter student name:\n ");
if( scanf(" %" STR_VALUE(MAX_NAME_LEN) "s",
studentGrades[ whichStudent ].name ) != 1 )
{
fprintf( stderr, "scanf for student name failed");
exit( EXIT_FAILURE );
}
// implied else, scanf for student name successful
printf("Student Name is: %s.",
studentGrades[ whichStudent ].name);
printf("please enter student class count:\n");
if( scanf(" %d", &studentGrades[ whichStudent ].class_num) != 1 )
{
fprintf( stderr, "scanf for student class count failed\n" );
exit( EXIT_FAILURE );
}
// implied else, scanf for student class count successful
printf("Student Number of classes: %d",
studentGrades[ whichStudent ].class_num);
// Input class grades
for( int whichClass=0;
whichClass < studentGrades[ whichStudent ].class_num;
whichClass++)
{
printf( "please enter grade for class: %d", whichClass );
if( scanf( " %c",
&(studentGrades[ whichStudent ].
grades[ whichClass ]) ) != 1)
{
fprintf( stderr,
"scanf for class grade %d failed\n",
whichClass );
exit( EXIT_FAILURE );
}
// implied else, scanf for class grade successful
printf( "student grade for class: %d is %d\n",
whichClass,
studentGrades[ whichStudent ].grades[ whichClass ] );
// following makes wild assumption that grade entered
// is 'A'...'F'
// Conversion of grades
float grade_point = 0.0f; // init for each class
switch( studentGrades[ whichStudent ].grades[ whichClass ] )
{
case 'A':
case 'a':
grade_point = 4.0f;
break;
case 'B':
case 'b':
grade_point = 3.0f;
break;
case 'C':
case 'c':
grade_point = 2.0f;
break;
case 'D':
case 'd':
grade_point = 1.0f;
break;
case 'F':
case 'f':
grade_point = 0.0f;
break;
default:
printf( "invalid grade entered\n");
whichClass--; // so will properly handle loop control, etc
break;
} // end switch
result += grade_point;
// Formula to calculate GPA
result += grade_point;
} // end for each grade
studentGrades[ whichStudent ].GPA =
result/(float)studentGrades[ whichStudent ].class_num;
} // end for each student
// Print user input and results in a table
printf( "\n Student name \tGPS\n\t\tgrades\n" );
for( size_t whichStudent=0;
whichStudent < (sizeof(studentGrades) / sizeof( struct studentGrade));
whichStudent++ )
{
if( 0 != strlen( studentGrades[ whichStudent ].name ) )
{
printf( " %s \tGPS: %.2f\n",
studentGrades[ whichStudent ].name,
studentGrades[ whichStudent ].GPA );
for( int whichClass=0;
whichClass < studentGrades[ whichStudent ].class_num;
whichClass++)
{
printf( "\tclass: %d\t%c:\n",
whichClass,
studentGrades[ whichStudent ].grades[ whichClass ] );
}
}
}
return 0;
}
答案 1 :(得分：1)
这个东西很少生锈，但我认为这里发生了一些奇怪的事情，可能并非有意。
for(g=0; g<=class_num; g++)
认为我们正在寻找存储在偏移c处的输入值，而不是数组。
for(c=0; c<10; c++)
我不太清楚这个循环的价值。我们每个学生只需要上课一次。
if (grade == "A")
同样，这并没有抓住数组中的正确偏移量。比较char需要单引号吗？
您还将打印出一堆打印报表...例如，您可能希望将此行移到循环之外：
printf("Please enter students' grades: %d.", grade[g]);
答案 2 :(得分：1)
所以，不要对你的案件进行判断，不论这是否是家庭作业，并且赞扬了Laughpine和Gopi已经说过的话......
您的代码中存在一些明显的错误，这些错误会阻止您编译和运行以产生任何影响。首先，让我们看看你的变量声明：
// Declare variables
// You don't initialize any of your char or int non array and array variables.
int grade[5], g, class_num[9], c;
char name[24], n;
float GPA=0.0, grade_point=0.0, result=0.0; // You initialize your floating point variables.
初始化时，编译器将指定这些变量所在的内存区域。如果你不这样做，那么编译器就会开始做出假设＆＃39;您正在使用的变量，并将随机内存位置分配给您的变量。下一个：
for (c = 0; c<10; c++) {
scanf(" %d", &class_num[c]); // You ask the user to enter one digit at a time for the class number
printf("Please enter amount of classes (max.10): %d", class_num[c]);
// Input grades
for (g = 0; g <= class_num; g++) // You try and make a comparison to a single variable int to an entire array which is not allowed.
{
scanf(" %d", &grade[g]);
printf("Please enter students' grades: %d.", grade[g]);
}
您无法将单个变量与整个数组进行比较，此行for (g = 0; g <= class_num; g++)将无法编译。另：
if (grade == "A"){
grade_point = 4.0;
}
您尝试从您的案例中作为int数据类型的成绩与不允许的字符串/字符文字"A"进行比较...
result += grade_point[g]
如果在此之前没有以这种方式定义，则Grade_point成为一个数组...
这看起来像是你匆匆完成了程序的设计过程。我建议你坐下来用一张纸和一支铅笔/笔，并在要求用户输入的每个阶段写出你想要完成的是什么。这将有助于定义您应该使用哪些变量数据类型来完成任务。