我正在做一项家庭作业,该作业使用外部文件计算 GPA 和课程平均值。代码并没有完全充实,但我已经构建了足够多的代码,它至少应该能够向我展示它可以从外部文件(在 TextWrangler 中创建的纯文本文件)中提取数据,并计算数字.
但是,当我运行它时,它似乎只会拉出输出文件的每一行。关于我可能出错的地方有什么想法吗?
#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
using namespace std;
int main()
{
int studentID, studentCounter=0;
double grade1, grade2, grade3, grade4, course1Sum=0, course2Sum=0, course3Sum=0, course4Sum=0, course1Average, course2Average, course3Average, course4Average, GPA;
ifstream inputFile;
string filename;
for (int x=1; x<=3; x++) {
// Get the filename from the user.
// /Users/etc/Desktop/HW5test.txt - valid set
// /Users/etc/Desktop/HW5testset.txt - test set
cout<<"Enter the filename: ";
cin>>filename;
// Open the file.
inputFile.open(filename.c_str());
// If the file successfully opened, process it.
if (inputFile) {
// Read the numbers from the file and display them.
while (inputFile>>studentID>>grade1>>grade2>>grade3>>grade4)
{
if (studentCounter==0) // Prints header if at the start of the program.
cout<<"Header placeholder"<<endl;
inputFile>>studentID>>grade1>>grade2>>grade3>>grade4;
GPA=(grade1+grade2+grade3+grade4)/4;
cout<<studentID<<" "<<GPA<<" "<<"Special message (if needed)."<<endl;
// Course Average and Student Accumulators
course1Sum+=grade1;
course2Sum+=grade2;
course3Sum+=grade3;
course4Sum+=grade4;
studentCounter++;
} // Ends while() loop.
if (studentCounter==0)
cout<<"File contains no data."<<endl;
else {
// Perform course averages here, after all data has been read.
course1Average=course1Sum/studentCounter;
cout<<"Course 1 average: "<<course1Average<<endl;
course2Average=course2Sum/studentCounter;
cout<<"Course 2 average: "<<course2Average<<endl;
course3Average=course3Sum/studentCounter;
cout<<"Course 3 average: "<<course3Average<<endl;
course4Average=course4Sum/studentCounter;
cout<<"Course 4 average: "<<course4Average<<endl<<endl;
} // Ends "else" of file empty error check.
// Close the input file.
inputFile.close();
} // Ends "if" of if/else().
else {
cout<<"Error opening the file.\n";
} // Ends "else" of if/else().
} // Ends for() loop.
return 0;
} // Ends main().
输入文件数据:
1001 3.0 2.7 2.0 2.8
1002 3.7 3.5 4.0 4.0
1003 0.0 1.0 2.2 1.0
1004 4.0 3.0 3.5 3.5
我的输出看起来像这样(请记住,仍在处理部分,但请注意它只是拉动所有其他条目:
Enter the filename: /Users/etc/Desktop/HW5testset.txt
Header placeholder
1002 3.8 Special message (if needed).
1004 3.5 Special message (if needed).
Course 1 average: 3.85
Course 2 average: 3.25
Course 3 average: 3.75
Course 4 average: 3.75
会发生什么?