在C ++中读取文件，搜索和显示信息到结构数组时出现问题 [英] Problem reading file,searching, and displaying information to an array of structures in C++
问题描述
很抱歉，如果这看起来很愚蠢，我是C ++的新手，我无法显示从输入文件读取到结构数组中的信息。
Sorry if this seems dumb, I am pretty new to C++ and I'm having trouble displaying information read into an array of structures from an input file.
我有3个功能。一个用于提示将我的文件读入数组，一个用于提示用户在数组中搜索特定的结构，最后一个用于显示数组的内容。
I have 3 functions. One for reading my file into the array, one for prompting the user to search for a specific struct in the array, and the last one for displaying the contents of the array.
我不确定我的 readFile（）或 displayAllStudents（）是否损坏。我可以从文件中输出第一行，但其余为0。接下来，我的 selectStudent（）可能很糟糕；我很难找到要解决的问题的好的解决方案。
I don't know for certain if my readFile() or displayAllStudents() is broken. I am able to output the first line from the file, but the rest is 0. Next my selectStudent() is probably terrible; I'm having trouble finding a good solution for what I'm trying to accomplish.
我尝试了许多此处发布的解决方案，但是我的问题似乎很特殊，所以我m希望我能帮助您指出正确的方向。
I've tried many solutions posted here, but my issue seems unique so I'm hoping I can help pointed in the right direction.
Input file and desired output.
ID CLA OLA Quiz Homework Exam Bonus Total FinalGrade
c088801 10 15 4 15 56 5
c088802 9 12 2 11 46 2
c088803 8 10 3 12 50 1
c088804 5 5 3 10 53 3
c088805 3 11 1 10 45 0
c088806 8 14 2 11 40 -1
c088807 4 12 2 12 48 -2
c088808 10 10 3 11 36 0
c088809 8 8 3 11 39 0
c088810 6 9 4 9 47 3
c088811 8 7 3 13 41 3
c088812 4 11 3 11 37 1
c088813 9 15 2 8 50 2
c088814 8 12 2 10 48 4
c088815 6 8 1 7 45 1
c088816 7 7 2 6 51 2
c088817 8 9 2 12 38 2
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
struct Student {
char ID[7];
int CLA;
int OLA;
int Quiz;
int Homework;
int Exam;
int Bonus;
int Total;
int FinalGrade;
};
const int SIZE = 20;
//Function prototypes
void readFile(Student[]);
int selectStudent(Student[]);
void displayAllStudents(Student[]);
int main() {
Student Roster[SIZE] = {}; //Initalizes array
readFile(Roster);
//selectStudent(Roster);
displayAllStudents(Roster);
system("pause");
return 0;
}
//This function will read the text file into our array of structures.
void readFile(Student Roster[]) {
ifstream inFile("point.dat"); //Reads input file
string line;
getline(inFile, line); //Skips first line of file
for (int i = 0; i < SIZE; i++) {
inFile >> Roster[i].ID >> Roster[i].CLA >> Roster[i].OLA >>
Roster[i].Quiz >> Roster[i].Homework >> Roster[i].Exam >>
Roster[i].Bonus >> Roster[i].Total >> Roster[i].FinalGrade;
}
}
//This function will prompt user to select an individual student ID
//then display that student's information.
int selectStudent(Student Roster[]) {
char* cNumber;
cout << "Please enter the student's c-number:" << endl;
cin >> cNumber;
for(int i; i < SIZE; i++){
if(strcmp(Roster[i].ID, cNumber)==0){
return i;
}
}
return -1;
}
//This function will display all our student information
void displayAllStudents(Student Roster[]) {
cout << " ID CLA OLA Quiz Homework Exam Bonus Total FinalGrade" << endl;
for (int i = 0; i < SIZE; i++) {
cout << Roster[i].ID[0] << Roster[i].ID[1] << Roster[i].ID[2] << Roster[i].ID[3] << Roster[i].ID[4] << Roster[i].ID[5] << Roster[i].ID[6]
<< " " << Roster[i].CLA << " " << Roster[i].OLA << " " << Roster[i].Quiz << " " <<
Roster[i].Homework << " " << Roster[i].Exam << " " << Roster[i].Bonus << " " <<
Roster[i].Total << " " << Roster[i].FinalGrade << endl;
}
}
My output.
ID CLA OLA Quiz Homework Exam Bonus Total FinalGrade
c088801 10 15 4 15 56 5 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
Press any key to continue . . .
推荐答案
在 readFile ，当您在此处读取文件的内容时，已假定每个Student结构的所有字段都包含数据。
In readFile, when you're reading the contents of your file here, you've assumed that all fields for every Student struct contain data.
inFile >> Roster[i].ID >> Roster[i].CLA >> Roster[i].OLA >>
Roster[i].Quiz >> Roster[i].Homework >> Roster[i].Exam >>
Roster[i].Bonus >> Roster[i].Total >> Roster[i].FinalGrade;
由于您输入的内容在总计和。 FinalGrade 列，当您的程序显示>>名册[i]。总计第一次实际上是试图读取第二个学生的id， c088802 ，它不是
Since your input doesn't have content in the Total and FinalGrade columns, when your program hits >> Roster[i].Total for the first time it's actually trying to read the second student's id, c088802, which isn't the integer value expected by Roster[i].Total.
如果您知道输入数据将永远不会包含在 Total 和 FinalGrade 列，则可以删除>>名册[i]。总数>>名单[i] .FinalGrade 从文件读取循环开始。
If you know your input data will never have content in the Total and FinalGrade columns, you can remove >> Roster[i].Total >> Roster[i].FinalGrade from your file read loop.
如果您知道输入数据可能不完整，但不知道行中将填充多少行，虽然可能有更好的方法，但类似的事情应该起作用。
If you know your input data might not be complete, but don't know how much of the row will be filled, something like this should work, though there's likely a better way.
for (int i = 0; i < SIZE; i++) {
getline(infile, line);
stringstream ss(line);
ss >> Roster[i].ID;
int value, count = 0;
while(ss >> value){
switch(count)
{
case 0: Roster[i].CLA = value;
break;
case 1: Roster[i].OLA = value;
break;
case 2: Roster[i].Quiz = value;
break;
...
case 7: Roster[i].FinalGrade = value;
break;
}
++count;
}
}
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