Problem about using class member function to read text file

allenfanwenyuan · #1 14-Sep-2007, 07:45

The question required to read some values from a text file. a example of text file is following(Student ID, 3 Assigments scores and final exam score);

s0000001 12 12 12 170
s9100002 9 7 10 135
s8000001 10 10 10 179
s9005004 6 9 6 150
s7000001 10 10 10 136

Now , I have a header file below,but I have no idea how to write member function to read those values from text file.

CPP / C++ / C Code:

#ifndef unit_H
#define unit_H

// don't modify this header file
// don't upload this file
// a class for a unit type

using namespace std;

class unitType
{
  public:
    unitType() {assignment1 =0; assignment2 = 0; assignment3 = 0; assSum = 0; exam = 0; total = 0;}; // deafult constructor
    void setUnit(float ***1, float ***2, float ***3, float ex);  // set values of data members
    void calAssSum();     // calculate assSum which is no more than 30
    void calTotal();      // calculate total, which is the sum of assSum (30%) and exam (70%).
    float getAssignment1() const;  // return assignment 1 score
    float getAssignment2() const;  // return assignment 2 score
    float getAssignment3() const;  // return assignment 3 score
    float getAssSum() const;       // return the value of assSum
    float getExam() const;         // return the value of exam
    float getTotal() const;        // return the value of total
         
  private:
    float assignment1, assignment2, assignment3; // scores for 3 assignments - in the scope of [0,12]
    float assSum, exam, total;  // assSum is the sum of 3 assignments score in the scope of [0,30]
                                // exam is the exam score in the scope of [0,180] - it is counted as 70% in total score
                                // total is the total score in the scope of [0,100] - 30% for assignments, 70% for the exam
};

#endif

Asking for anyone can help!! cheers!

Kimmo · #2 14-Sep-2007, 13:53

Quote:

Originally Posted by allenfanwenyuan

Now , I have a header file below,but I have no idea how to write member function to read those values from text file.

Is the problem in the part of writing the method or in the part of reading the file or in the part of parsing the data in the file or..?

CPP / C++ / C Code:

    void setUnit(float ***1, float ***2, float ***3, float ex);

Guess this is some kind of a forum filter issue? Doesn't make much sense otherwise..

Just for curiosity, I don't get this part

CPP / C++ / C Code:

float assignment1, assignment2, assignment3; // scores for 3 assignments - in the scope of [0,12]
float assSum, exam, total; // assSum is the sum of 3 assignments score in the scope of [0,30]
// exam is the exam score in the scope of [0,180] - it is counted as 70% in total score
// total is the total score in the scope of [0,100] - 30% for assignments, 70% for the exam

Does this mean that 3 * 12 = 30? Does it also mean that 180 * 0.7 + 32 * 0.3 = 100?

Or does it mean that total score = 30 * (assSum / 30) + 70 * (exam / 180)?

allenfanwenyuan · #3 14-Sep-2007, 22:27

Kimmo
The question is to get and calculate each student's final score which including 3 assignment scores(contributes 30%) and final exam score(contributes 70). If total assignment score is greater than 30 , it will be counted 30, if less than 30 ,like 25 ,the total assignment score will be remain 25. The exam score will be scale down to 70, that means , 180 =70, 90=35. So the maximum of final score is still 100.

I am confused how to write definition to get each assignment score and final exam score from a text file. I wrote some belwo ,but seems not corret.

CPP / C++ / C Code:

#include <iostream>
#include <iomanip>
#include <string>

#include "unitType.h"

using namespace std;

// implement all member functions of class unitType - check "unitType.h"
void unitType::setUnit(float ***1,float ***2,float ***3,float ex)
{
     assignment1=***1;
     assignment2=***2;
     assignment3=***3;
     exam=ex;
     }
                    
void unitType::calAssSum()
{
     assSum=assignment1+assignment2+assignment3;
     if(assSum>30)
     assSum=30;
}

void unitType::calTotal()
{
     total=assSum+exam/180*70;
}

float unitType::getAssignment1() const
{
      return assignment1;
}    
                
float unitType::getAssignment2() const
{
      return assignment2;
}   
float unitType::getAssignment3() const
{
      return assignment3;
}   
float unitType::getAssSum() const
{
      return assSum;
}
float unitType::getExam() const
{
      return exam;
}   
float unitType::getTotal() const
{
      return total;
}

Kimmo · #4 15-Sep-2007, 06:20

Quote:

Originally Posted by allenfanwenyuan

I wrote some belwo ,but seems not corret.

Yes, well clearly it is not correct since there isn't anything that even possibly could read anything from a file. I get the feeling you're trying to get someone else to write the program for you.

Now when I look at that header file, it seems to me that the intention is not to read the data in a method. The intention is just to pass the data (sounds reasonable, no use making unitType a database manager.)

So try something like this in your main()

Code:

open file
if file not open, quit
read data from file
pass data to unitType object
process

If the data in file is guaranteed to be ordered as you showed, then reading the data could be done with something like follows:

CPP / C++ / C Code:

while (ifstreamName)
{
    string temp;
    float score1, score2, score2, exam;

    ifstreamName >> temp >> score1 >> score2 >> score3 >> exam;

// Do something with the data
}

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Problem about using class member function to read text file

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