problem with classes - Dev Articles

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March 27th, 2005, 05:50 PM

tooliscrowned

Registered User

Join Date: Mar 2005

Posts: 5

Time spent in forums: 1 h 3 m 21 sec
Reputation Power: 0

problem with classes

i am trying to write a program that does the following:

asks for name
asks for number of classes taken at school
asks for grade of each class

displays name
displays each class number and grade.

i am getting several errors when i try to compile, mostly
"ostream:

perator" type errors ( i am using DJGPP)

i know there must be something very basic i am skipping over...
also there are probably some syntax errors because after it didn't work the first time i tried re-writing some parts, and then just got even more errors.

Code:

 #include <iostream.h>
 
 class school
 {
 public:
 
 school() 			{}
 ~school()			{}
 void setcl(int x); 		
 void gpa(int x, int y)	{yourgpa=(x/y);}
 
 float sendgpa(void)	 const	{return yourgpa;}
 int sendgrades(int x) const 	{return yourgrades[x];}
 
 private:
 
 int yourgrades[10];
 float yourgpa;
 
 
 };
 
 void school::setcl(intx)
 {
 int y;
 for (y=1; y<(x+1); y++)
 {
 cout << "Enter grade for class " << y;
 cin << yourgrades[(y-1)];
 }
 }
 
 int main()
 {
 school boy;
 int i=0;
 int y;
 int total=0;
 int cl;
 float gpa;
 char name [50];
 
 
 cout << "Enter your name: " << endl;
 cin.get(name, 49);
 
 do
 {
 cout << "Enter the number of classes you take: " << endl
 cin >> cl;
 }while ((cl > 11) || (cl < 0));
 
 boy.setcl(cl);
 
 
 for (i=0; i<cl; i++)
 {
 total = boy.sendgrades(i) + total;
 }
 boy.gpa(total, cl);
 
 cout << "Name: " << name << endl;
 
 for (i=0; i < (cl+1); i++)
 {
 
 cout << "Class" << i+1 << ": " << boy.sendgrades(i) << endl;
 
 }
 
 cout << "Your GPA: " << boy.sendgpa;
 
 return 0;
 }

please help.

March 27th, 2005, 09:37 PM

ubergeek

Contributing User

Join Date: Jan 2005

Posts: 600

Time spent in forums: 2 Days 22 h 40 m 27 sec
Reputation Power: 4

here you are

mainly you just had some typos in your code.

Code:

 #include <iostream> //with c++, the headers drop the .h (don't ask me why, they are just updated somehow)
 using namespace std; //with the no-.h headers, you need to include this statement. google "c++ namespaces" or something for more information.
  
  class school
  {
  public:
  
  school() 			{}
  ~school()			{}
  void setcl(int x); 		
  void gpa(int x, int y)	{yourgpa=(x/y);}
  
  float sendgpa(void)	 const	{return yourgpa;}
  int sendgrades(int x) const 	{return yourgrades[x];}
  
  private:
  
  int yourgrades[10];
  float yourgpa;
  
  
  };
  
  void school::setcl(int x) //probably a typo, you missed the space between "int" and "x"
  {
  int y;
  for (y=1; y<(x+1); y++)
  {
  cout << "Enter grade for class " << y;
  cin >> yourgrades[(y-1)]; //most likely another typo: when using cin, use >> instead of <<
  }
  }
  
  int main()
  {
  school boy;
  int i=0;
  int y;
  int total=0;
  int cl;
  float gpa;
  char name [50];
  
  
  cout << "Enter your name: " << endl;
  cin.get(name, 49);
  cin.ignore(); //cin.get() doesn't remove the delimiting character (in this case, a linebreak) from the keyboard buffer, so without this statement (which clears the buffer) it skips the next name
  
  do
  {
  cout << "Enter the number of classes you take: " << endl;
  cin >> cl;
  }while ((cl > 11) || (cl < 0));
  
  boy.setcl(cl);
  
  
  for (i=0; i<cl; i++)
  {
  total = boy.sendgrades(i) + total;
  }
  boy.gpa(total, cl);
  
  cout << "Name: " << name << endl;
  
  for (i=0; i < (cl+1); i++)
  {
  
  cout << "Class" << i+1 << ": " << boy.sendgrades(i) << endl;
  
  }
  
  cout << "Your GPA: " << boy.sendgpa(); //make sure you include the parenthese in function calling, even when there are no parameters. otherwise the compiler interprets it as a function pointer.
  
  return 0;
  }

this compiles and runs for me in bloodshed dev-c++ 4.9.9.2

as you can see, I did not modify anything in your code except minor typos. i left comments wherever i fixed stuff. however, your program still does not work quite right--I said I had 2 classes, and entered a grade of 4 for both, and the output was

Quote:

Originally Posted by XP SP2 cmd.exe

Name:aaaaa
Class 1:4
Class 2:4
Class 3:8
GPA:4

or something like that. as you can see, where it displays class 3 that should be total or something to that effect. also, i find it counterintuitive that i have to enter grades in numerical format. it would be easy enough to accept a 2-character string (letter and +/-) and write a function to convert that to a number. but it is your program and I am leaving these minor finishing touches to you. Of course, if you try and have more questions, then by all means post back here and I and others will help you out.

March 28th, 2005, 12:49 PM