Another class assignment, please help.

**WinterInChicago** · 11-04-2006

Here is my assignment and the code I have written so far. Please tell me what else needs to be done. Also, I do not understand sentinal controlled loops.

CSCI 1010 Programming Assignment 7

Purpose:
Write a C++ program that uses strings, reference parameters from Chapter 9 and while loop from Chapter 7 with a sentinel value (see pages 163-165).
Due Date: The program is due by 8 p.m. on Monday 11/6/06.
Assignment:
White a C++ program that will input a student’s name and 3 test grades. It will compute the average grade for the student, write out the student’s name, three test scores, and average grade. The program must use the following 3 functions in addition to the main function:

1. a void function to read in the student’s name as a string and pass it back as a reference parameter.

2. a double function that reads in the three test scores ,computes the average and passes back the 3 test scores via reference parameters and the average as the value of the double function.

3. a void function that displays the output data (student’s name, 3 test grades and average grade) with appropriate labels.

The program must use a sentinel controlled loop. The program should continue processing students until and uppercase DONE is entered for the student’s name. When DONE is entered, no test scores are to be read or processed. The program is to end.

D. Sample Run where the bold data was entered by the user

Enter student’s name or DONE to quit: John Smith

Enter 3 test scores: 85 90 77

Student: John Smith

Three test scores: 85 90 77

Average grade: 84.00

Enter student’s name or DONE to quit: Jim Mirth

Enter 3 test scores: 95 90 79

Student: Jim Mirth

Three test scores: 95 90 79

Average grade: 88.00

Enter student’s name or DONE to quit: DONE

Code:

#include <iostream>
using namespace std;

void name (string & student);
//Void function to read name and pass back as ref.

double avg (double & gradea, double & gradeb, double & gradec);
//Function 2 - computes average and passes back scores via reference par.

void displaystuff (string student, double gradea, double gradeb, double gradec, double averagex);
//Function 3 - Display the Information.

int main ()
        {//int main open
        string name;
        double gradeone, gradetwo, gradethree, average;
        cout << "Enter Student Name or DONE to Quit:" << endl;
        cin. ignore (80, '\n');
        getline (cin, name);
                while (name != DONE)
                {//while loop open
                cout << "Enter 3 Test Scores:" << endl;
                cin >> gradeone >> gradetwo >> gradethree;
                average = avg (gradeone, gradetwo, gradethree);
                displaystuff (name, gradeone, gradetwo, gradethree, average);

                cout << "Enter Student Name or DONE to Quit:" << endl;
                cin. ignore (80, '\n');
                getline (cin, name);
                }//while loop close
        }//int main close

void name (string & student)

double avg (double & gradea, double & gradeb, double & gradec)
        {//function open
        double averaged, added;
        added = gradea + gradeb + gradec;
        averaged = added/3;
        return averaged;
        }//function closed

void displaystuff (string student, double gradea, double gradeb, double gradec, double averagex)
        {//void function open
        cout << "Student: " << student << endl;
        cout << "Three Test Scores: " << gradea << " " << gradeb << " " << gradec << endl;
        cout << setiosflags (ios::fixed|ios::showpoint) << setprecision (2);
        cout << "Average Grade: " << averagex << endl;
        }//void function close

**anon** · 11-04-2006

2. a double function that reads in the three test scores ,computes the average and passes back the 3 test scores via reference parameters and the average as the value of the double function.

I think you should ask the test scores in this function, not in main, otherwise the references have no point.

name is a std::string. You must compare it against another string. Literal strings go between double quotes ("DONE").

**WinterInChicago** · 11-04-2006

i cant do std::string. she hasnt covered it in that way. she requires using namespace std; but thank you for the rest of your post.

**Mario F.** · 11-04-2006

anon is referring to the qualified name of C++ strings, out of habit (I believe). It helps in any conversation since it immediatly establishes we aren't talking about c-style strings.

**dwks** · 11-04-2006

Your name() function doesn't have a body.

To use std::strings (or C++ style strings, if you prefer), you need to include the header file <string>; likewise, I think setiosflags() is in <iomanip> (Input/Output Manipulation).

Code:

int main ()
        {//int main open
        string name;
        double gradeone, gradetwo, gradethree, average;
        cout << "Enter Student Name or DONE to Quit:" << endl;
        cin. ignore (80, '\n');
        getline (cin, name);

You're ignore()ing before any input functions.

**WinterInChicago** · 11-05-2006

i have no idea what any of you just said. im in intro to programming and the prof teaches us bare minimum information.

**Salem** · 11-05-2006

> void name (string & student)
This function doesn't have a body, so the code won't even compile

> string name;
This is the same name as your function.
Pick more meaningful identifiers, and make sure they don't clash.

> while (name != DONE)
As already stated
while (name != "DONE" )

**manutd** · 11-05-2006

AKA make it like this:

Code:

void name (string& student)
{
     cout << "Enter the student's name or DONE to quit:" << endl;
     getline(cin, student);
     cin.ignore(80,'\n');
}

Then in main take out this:

Code:

cout << "Enter Student Name or DONE to Quit:" << endl;
cin. ignore (80, '\n');
getline (cin, name);

And then replace it with this:

Code:

name(name);

**Mario F.** · 11-05-2006

Originally Posted by manutd

AKA make it like this:

Code:

void name (string& student)
{

[...]
And then replace it with this:

Code:

name(name);

No, no, no. Read Salem's 2nd advice

**manutd** · 11-05-2006

I know, I just wanted to stick with what he wrote. I he wants to improve his code, that's his job. It probably should be void getstudent (string& student) and studentname.

**WinterInChicago** · 11-06-2006

Have I made any progress?

Code:

#include <iostream>
#include <iomanip>
using namespace std;

void getname (string & student);
//Void function to read name and pass back as ref.

double avg (double & gradea, double & gradeb, double & gradec);
//Function 2 - computes average and passes back scores via reference par.

void displaystuff (string student, double gradea, double gradeb, double gradec, double averagex);
//Function 3 - Display the Information.

int main ()
        {//int main open
        string name;
        double gradeone, gradetwo, gradethree, average;
        getname (name);
        while (name != DONE)
                {//while loop open
                avg (gradeone, gradetwo, gradethree);
                average = avg (gradeone, gradetwo, gradethree);
                displaystuff (name, gradeone, gradetwo, gradethree, average);
                getname (name);
                }//while loop close
        }//int main close

void getname (string & student)
        {//function open
        cout << "Enter the student's name or DONE to quit:" << endl;
        getline(cin, student);
        cin.ignore(80,'\n');
        }//function close

double avg (double & gradea, double & gradeb, double & gradec)
        {//function open
        cout << "Enter 3 Test Scores:" << endl;
        cin >> gradea >> gradeb >> gradec;
        double averaged, added;
        added = gradea + gradeb + gradec;
        averaged = added/3;
        return averaged;
        }//function closed

void displaystuff (string student, double gradea, double gradeb, double gradec, double averagex)
        {//void function open
        cout << "Student: " << student << endl;
        cout << "Three Test Scores: " << gradea << " " << gradeb << " " << gradec << endl;
        cout << setiosflags (ios::fixed|ios::showpoint) << setprecision (2);
        cout << "Average Grade: " << averagex << endl;
        )

**Cat** · 11-06-2006

1. You need to #include <string>

2. You don't need 2 calls to avg().

3. You should probably rename avg(), it's kind of misleading because the real thing it's doing is reading the scores in; the averaging is more of a secondary function.

4. You might want to make the average also a reference parameter and return it that way; it gets kind of confusing when you're returning some data through references and another piece through return values; usually on functions that return data by references/pointers, the return value is just a success/failure code (or void if it can't fail).

5. You can combine some statements; for example:
averaged = (gradea + gradeb + gradec) / 3;

**manutd** · 11-06-2006

This is not correct:

Code:

while (name != DONE

It should be this:

Code:

while (name != "DONE" )

This has already been stated many times. Also, I would like displaystuff to be something like showstudentinfo. But thats me.

**WinterInChicago** · 11-06-2006

disregard what was previously here, thanks for hte help im done.

**WinterInChicago** · 11-09-2006

i wish i could edit my first post. i think one of my classmates snatched my code off here and i dont want that.

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