我是一名学生,正在研究一个涉及数组、指针、结构和去/引用的问题。我了解每个单独的含义和每个的一般初始化,但我觉得我仍然没有在我的程序中正确使用它们。我运行/工作得很好,但我想知道是否有更好的方法来使用这些?
一般程序要求如下:(我已经包含了我认为涵盖每个问题的行。我想确保我正在使用每一行并将其正确地合并到程序中。主要是我正在使用的地方StudentData[i].testArray
)
1 - 使用结构存储以下数据:名称、id#、测试(指向测试分数数组的指针)、平均、字母等级。
struct StudentData {...};
2 - 询问学生人数和考试次数(每个学生相同)
3 - 动态分配结构数组
StudentData *allStudents;
allStudents = new StudentData[numStudents];
4 - 每个结构的 Tests 成员应指向一个动态分配的测试分数数组。
double *testsArray;
for (int i=0; i < numStudents; i++)
{
allStudents[i].testsArray = new double[numTests];
}
//does this need to be deleted with a for loop as well??
5 - 计算测试平均分和字母等级
6 - 显示信息
完整代码:
// Course Grade
// A program to gather and display a collection of student information.
// Programmer Name : Chuck
// C++ II
#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
//structure to hold data for each student
struct StudentData
{
string studentName;
int studentID;
double *testsArray; //pointer to an array of test scores
double testAverage; //calculated average test score
char courseGrade; //calculated course letter grade (A-F)
};
//function prototypes
string getName();
int getID();
double getScore(int count);
char calcGradeLetter(double *testAverage);
void displayData (StudentData allStudents[], int sCount);
int main()
{ cout << " Welcome to the Test Score Storer. This program will gather test\n";
cout << "scores for a given student name/id#. We'll start with some questions.\n\n";
int numTests;
cout << "How many test scores per student? : ";
cin >> numTests;
int numStudents;
cout << "How many students? : ";
cin >> numStudents;
cout << "Creating Database...";
//create array to hold all studentData structs
StudentData *allStudents;
allStudents = new StudentData[numStudents];
cout << "...";
//create a tests member array for each student struct
double *testsArray;
for (int i=0; i < numStudents; i++)
{
allStudents[i].testsArray = new double[numTests];
}
cout <<"...Done!\n";
system ("pause");
system ("CLS");
//TRYING
for (int i=0; i < numStudents; i++)
{
cout << "Student " << i+1 << " of " << numStudents << endl;
cout << "=================================\n";
allStudents[i].studentName = getName();
allStudents[i].studentID = getID();
double testTotal = 0.0;
for (int j=0; j < numTests; j++)
{
allStudents[i].testsArray[j] = getScore(j);
testTotal += allStudents[i].testsArray[j];
allStudents[i].testAverage = testTotal/numTests;
}
//calculate letter grade
allStudents[i].courseGrade = calcGradeLetter(&allStudents[i].testAverage);
cout << "Student, " << allStudents[i].studentName << ", completed.\n";
system ("pause");
system ("CLS");
}
//Display all collected student data in chart form
displayData(allStudents, numStudents);
delete [] allStudents;
system ("pause");
return (0);
}
//===========FUNCTIONS===========FUNCTIONS===========FUNCTIONS
string getName()
{
string name;
cout << "Student Name : ";
cin >> name;
return name;
}
int getID()
{
int IDnum;
cout << "Student ID : ";
cin >> IDnum;
return IDnum;
}
double getScore(int count)
{
double score;
score = -500;
while (score <0)
{ cout << "Test Score #" << count+1 <<" : ";
cin >> score;
if (score < 0)
{
cout << "Scores cannot be less than 0, try again.\n";
}
}
return score;
}
char calcGradeLetter(double *testAverage)
{
if (*testAverage >= 90) return 'A';
else if (*testAverage >= 80) return 'B';
else if (*testAverage >= 70) return 'C';
else if (*testAverage < 70) return 'F';
else return ('X');
}
void displayData(StudentData allStudents[], int sCount)
{
cout << "Student Data Chart:\n";
cout << "=================================================\n";
cout << "NAME ID# TEST AVE. GRADE\n";
for (int i = 0; i < sCount; i++)
{
cout << left << setw(18) << allStudents[i].studentName << " "
<< left << setw(12) << allStudents[i].studentID << " "
<< left << setw(11) << setprecision(4) << allStudents[i].testAverage << " "
<< allStudents[i].courseGrade << endl;
}
cout << "\nTable complete. ";
}
这是我在 Stack 上的第一篇文章,如果出现在错误的地方或需要家庭作业,我很抱歉,我不只是在寻找一个简单的答案。我是一名新开发人员,渴望学习。这个话题只是我在处理时遇到了很多麻烦。