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Simple array/class problem (dot operator)???

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Join Date: Apr 2005

Posts: 2

Reputation: k0ld is an unknown quantity at this point

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k0ld

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Simple array/class problem (dot operator)???

Apr 4th, 2005

Here is the code:

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#include <iostream>
#include <cstdlib>
using namespace std;
class student 
{
public:
  void inputScores(); // Prompts user to enter 2 quiz, a mid term, and a final score; store 
  // them in corresponding data members.
  void computeGrade(); // Compute average and then convert the average to letter grade
  void displayRecord(); // Displays the name; two quiz, midterm, and final scores; letter grade 
  // of a student in a single row, e.g., John 95 85 90 90 90 A
private:
  string name;
  int quiz1; // 0 - 10
  int quiz2; // 0 - 10
  int midterm; // 0 - 100
  int final; // 0 – 100
  float average;
  char grade; // letter grade: A, B, C, D, or F
  int num;
  int i;
};
 
int main()
{
  int test;
  const int SIZE = 10;
  student stats;
  student s[SIZE];
 
  stats.inputScores();
  stats.computeGrade();
  stats.displayRecord();
  cin >> test;
  return 0;
 
};
void student::displayRecord()
{
  cout <<"\n\n\nQuiz1 Quiz2 Midterm Final Average Grade Name" << endl;
  cout <<"_____ _____ _______ _____ _______ _____ ____" << endl;
 
  for ( i = 0; i < num; i++)
  {
    cout << s.quiz1[i] << " " << s.quiz2[i] <<" " << s.midterm[i] <<" "; 
    cout << s[i].final << " " << s[i].average << " " << s[i].grade << " ";
    cout << s[i].name << endl;
  }
}
 
 
void student::computeGrade()
{
  float quizaverage, midtermaverage, finalaverage;
 
  for ( i = 0; i < num; i++)
  { 
    quizaverage = ((s[i].quiz1 + s[i].quiz2) / 2) * .25; 
    midtermaverage = s[i].midterm * .25;
    finalaverage = s[i].final * .5;
    s[i].average = quizaverage + midtermaverage + finalaverage; 
 
    if (average >= 90 && average <= 100)
      grade = 'A';
    else if (average >= 80 && average <= 89) 
      grade = 'B';
    else if (average >= 70 && average <= 79) 
      grade = 'C';
    else if (average >= 60 && average <= 69) 
      grade = 'D';
    else
      grade = 'F';
  }
}
void student::inputScores()
{
 
  cout << "Enter the number of students whose grades you wish to compute: ";
  cin >> num;
  for (i = 0; i < num; i++)
  {
    cout <<"\nEnter the students name: ";
    cin >> s.name[i];
    cout << "\nEnter the first quiz grade: ";
    cin >> s.quiz1[i];
    cout << "\nEnter the second quiz grade: ";
    cin >> s.quiz2[i];
    cout << "\nEnter your midterm grade: ";
    cin >> s.midterm[i];
    cout << "\nEnter your final test grade: ";
    cin >> s.final[i];
  } 
}
#include <iostream>
#include <cstdlib>
using namespace std;
class student 
{
public:
  void inputScores(); // Prompts user to enter 2 quiz, a mid term, and a final score; store 
  // them in corresponding data members.
  void computeGrade(); // Compute average and then convert the average to letter grade
  void displayRecord(); // Displays the name; two quiz, midterm, and final scores; letter grade 
  // of a student in a single row, e.g., John 95 85 90 90 90 A
private:
  string name;
  int quiz1; // 0 - 10
  int quiz2; // 0 - 10
  int midterm; // 0 - 100
  int final; // 0 – 100
  float average;
  char grade; // letter grade: A, B, C, D, or F
  int num;
  int i;
};

int main()
{
  int test;
  const int SIZE = 10;
  student stats;
  student s[SIZE];

  stats.inputScores();
  stats.computeGrade();
  stats.displayRecord();
  cin >> test;
  return 0;

};
void student::displayRecord()
{
  cout <<"\n\n\nQuiz1 Quiz2 Midterm Final Average Grade Name" << endl;
  cout <<"_____ _____ _______ _____ _______ _____ ____" << endl;

  for ( i = 0; i < num; i++)
  {
    cout << s.quiz1[i] << " " << s.quiz2[i] <<" " << s.midterm[i] <<" "; 
    cout << s[i].final << " " << s[i].average << " " << s[i].grade << " ";
    cout << s[i].name << endl;
  }
}


void student::computeGrade()
{
  float quizaverage, midtermaverage, finalaverage;

  for ( i = 0; i < num; i++)
  { 
    quizaverage = ((s[i].quiz1 + s[i].quiz2) / 2) * .25; 
    midtermaverage = s[i].midterm * .25;
    finalaverage = s[i].final * .5;
    s[i].average = quizaverage + midtermaverage + finalaverage; 

    if (average >= 90 && average <= 100)
      grade = 'A';
    else if (average >= 80 && average <= 89) 
      grade = 'B';
    else if (average >= 70 && average <= 79) 
      grade = 'C';
    else if (average >= 60 && average <= 69) 
      grade = 'D';
    else
      grade = 'F';
  }
}
void student::inputScores()
{

  cout << "Enter the number of students whose grades you wish to compute: ";
  cin >> num;
  for (i = 0; i < num; i++)
  {
    cout <<"\nEnter the students name: ";
    cin >> s.name[i];
    cout << "\nEnter the first quiz grade: ";
    cin >> s.quiz1[i];
    cout << "\nEnter the second quiz grade: ";
    cin >> s.quiz2[i];
    cout << "\nEnter your midterm grade: ";
    cin >> s.midterm[i];
    cout << "\nEnter your final test grade: ";
    cin >> s.final[i];
  } 
}

Code indented and tags added. -Narue

As you can see, I attempted both ways using s.quiz1[i] and s[1].quiz1 however both turned up as errors saying I need to declare S in a function first??? I owe you big time to whoever can help me out with this.

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Join Date: Mar 2005

Posts: 22

Reputation: Auto is an unknown quantity at this point

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Auto

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Newbie Poster

Re: Simple array/class problem (dot operator)???

Apr 4th, 2005

First off your s[i].quiz1 is the way to go, but your function can not see it unless you either pass it via function argument or make it external. Here's how I got your program to work. Try making the highlighted changes.

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#include <iostream>
#include <cstdlib>
using namespace std;
class student 
{
public:
   void inputScores(); // Prompts user to enter 2 quiz, a mid term, and a final score; store 
   // them in corresponding data members.
   void computeGrade(); // Compute average and then convert the average to letter grade
   void displayRecord(); // Displays the name; two quiz, midterm, and final scores; letter grade 
   // of a student in a single row, e.g., John 95 85 90 90 90 A
private:
   string name;
   int quiz1; // 0 - 10
   int quiz2; // 0 - 10
   int midterm; // 0 - 100
   int final; // 0 – 100
   float average;
   char grade; // letter grade: A, B, C, D, or F
   int num;
   int i;
};

const int SIZE = 10;
student s[SIZE];

int main()
{
   int test;
   student stats;

   stats.inputScores();
   stats.computeGrade();
   stats.displayRecord();
   cin >> test;
   return 0;
};
void student::displayRecord()
{
   cout <<"\n\n\nQuiz1 Quiz2 Midterm Final Average Grade Name" << endl;
   cout <<"_____ _____ _______ _____ _______ _____ ____" << endl;

   for ( i = 0; i < num; i++)
   {
      cout << s[i].quiz1  << " " << s[i].quiz2  <<" " << s[i].midterm  <<" "; 
      cout << s[i].final << " " << s[i].average << " " << s[i].grade << " ";
      cout << s[i].name << endl;
   }
}


void student::computeGrade()
{
   float quizaverage, midtermaverage, finalaverage;

   for ( i = 0; i < num; i++)
   { 
      quizaverage = ((s[i].quiz1 + s[i].quiz2) / 2) * .25; 
      midtermaverage = s[i].midterm * .25;
      finalaverage = s[i].final * .5;
      s[i].average = quizaverage + midtermaverage + finalaverage; 

      if (s[i].average  >= 90 && s[i].average  <= 100)
         s[i].grade  = 'A';
      else if (s[i].average  >= 80 && s[i].average  <= 89) 
         s[i].grade  = 'B';
      else if (s[i].average  >= 70 && s[i].average  <= 79) 
         s[i].grade = 'C';
      else if (s[i].average  >= 60 && s[i].average  <= 69) 
         s[i].grade  = 'D';
      else
         s[i].grade  = 'F';
}
}
void student::inputScores()
{
   cout << "Enter the number of students whose grades you wish to compute: ";
   cin >> num;
   for (i = 0; i < num; i++)
   {
      cout <<"\nEnter the students name: ";
      cin >> s[i].name;
      cout << "\nEnter the first quiz grade: ";
      cin >> s[i].quiz1;
      cout << "\nEnter the second quiz grade: ";
      cin >> s[i].quiz2;
      cout << "\nEnter your midterm grade: ";
      cin >> s[i].midterm;
      cout << "\nEnter your final test grade: ";
      cin >> s[i].final;
   } 
}

#include <iostream>
#include <cstdlib>
using namespace std;
class student 
{
public:
   void inputScores(); // Prompts user to enter 2 quiz, a mid term, and a final score; store 
   // them in corresponding data members.
   void computeGrade(); // Compute average and then convert the average to letter grade
   void displayRecord(); // Displays the name; two quiz, midterm, and final scores; letter grade 
   // of a student in a single row, e.g., John 95 85 90 90 90 A
private:
   string name;
   int quiz1; // 0 - 10
   int quiz2; // 0 - 10
   int midterm; // 0 - 100
   int final; // 0 – 100
   float average;
   char grade; // letter grade: A, B, C, D, or F
   int num;
   int i;
};

const int SIZE = 10;
student s[SIZE];

int main()
{
   int test;
   student stats;

   stats.inputScores();
   stats.computeGrade();
   stats.displayRecord();
   cin >> test;
   return 0;
};
void student::displayRecord()
{
   cout <<"\n\n\nQuiz1 Quiz2 Midterm Final Average Grade Name" << endl;
   cout <<"_____ _____ _______ _____ _______ _____ ____" << endl;

   for ( i = 0; i < num; i++)
   {
      cout << s[i].quiz1  << " " << s[i].quiz2  <<" " << s[i].midterm  <<" "; 
      cout << s[i].final << " " << s[i].average << " " << s[i].grade << " ";
      cout << s[i].name << endl;
   }
}


void student::computeGrade()
{
   float quizaverage, midtermaverage, finalaverage;

   for ( i = 0; i < num; i++)
   { 
      quizaverage = ((s[i].quiz1 + s[i].quiz2) / 2) * .25; 
      midtermaverage = s[i].midterm * .25;
      finalaverage = s[i].final * .5;
      s[i].average = quizaverage + midtermaverage + finalaverage; 

      if (s[i].average  >= 90 && s[i].average  <= 100)
         s[i].grade  = 'A';
      else if (s[i].average  >= 80 && s[i].average  <= 89) 
         s[i].grade  = 'B';
      else if (s[i].average  >= 70 && s[i].average  <= 79) 
         s[i].grade = 'C';
      else if (s[i].average  >= 60 && s[i].average  <= 69) 
         s[i].grade  = 'D';
      else
         s[i].grade  = 'F';
}
}
void student::inputScores()
{
   cout << "Enter the number of students whose grades you wish to compute: ";
   cin >> num;
   for (i = 0; i < num; i++)
   {
      cout <<"\nEnter the students name: ";
      cin >> s[i].name;
      cout << "\nEnter the first quiz grade: ";
      cin >> s[i].quiz1;
      cout << "\nEnter the second quiz grade: ";
      cin >> s[i].quiz2;
      cout << "\nEnter your midterm grade: ";
      cin >> s[i].midterm;
      cout << "\nEnter your final test grade: ";
      cin >> s[i].final;
   } 
}

•

Join Date: Apr 2005

Posts: 2

Reputation: k0ld is an unknown quantity at this point

Solved Threads: 0

k0ld

Offline

Newbie Poster

Re: Simple array/class problem (dot operator)???

Apr 4th, 2005

Awesome, that worked out perfectly. I can't begin to tell you how appreciative I am for that...I'm pretty far behind in my CS240 class and was stuck on that assignment for hours. Thanks again.