Programming Forums > Application Development > C++

cwl157 · Jan 26th, 2006, 4:20 PM

I have to write a program that prompts the user to enter a course by department course number semester taken and what the final grade was. Then the user has the option to print the courses entered or check the courses entered against the requirements. Right now i am working on entering the courses and printing the courses entered. I can enter and print courses fine the first time. However, if i try to enter 1 course and then say print that course out. Then i ask to add another course and print that it should print both courses however it only prints the second course entered. I'm very new to C++ i just have some java experience so any help would be very appreciated. Heres the code:

(Toggle Plain Text)

#include <iostream>
#include <string.h>

using namespace std;

struct classInfo
{
  char department[2];
  int courseNumber;
  char semesterTaken[5];
  char grade;
};

struct classInfo clInfo[100];
int loc = 0;
int i = 0;

void print()
{
  while(i < loc)
  {
    cout << clInfo[i].department << "  "  
         << clInfo[i].courseNumber << "  " 
         << clInfo[i].semesterTaken << "  " 
         << clInfo[i].grade
         << endl;
    i++;

  }
  cout << endl;
}

void addClass ()
{
  cout << "Please enter the department code: ";
  cin >> clInfo[loc].department;
  cout << "Please enter the course number: ";
  cin >> clInfo[loc].courseNumber;
  cout << "Please enter the semester: ";
  cin >> clInfo[loc].semesterTaken;
  cout << "Please enter the grade earned: ";
  cin >> clInfo[loc].grade;
  cout << endl;
  loc++;

}

int main()
{
  int option;
  
  while(option !=4)
  {
    cout << "Please make a selection: \n"
         << "1. Add a new class. \n"
         << "2. Print your current list of classes. \n"
         << "3. Check your courses against the requirements. \n"
         << "4. Quit \n"
         << "Your selection: ";
    cin >> option;   
    cout << endl;

   if(option == 1)
     addClass(); 

   if(option == 2)
     print();
  }

  return 0;
}

jayme · Jan 26th, 2006, 4:28 PM

have you tried..

(Toggle Plain Text)

void print()
{
  while(i < loc)
  {
    cout << clInfo[i].department << "  "  
         << clInfo[i].courseNumber << "  " 
         << clInfo[i].semesterTaken << "  " 
         << clInfo[i].grade
         << endl;
    i++;

  }
  cout << endl;
}printnum;

int main()
{
int i = 0;
addClass();
if(addClass)
{
i += 1;
printnum[i];
}

I'm really hungry so not really into it as much, i hope you understand what i'm trying to say.

Jason Isom · Jan 26th, 2006, 5:20 PM

Quote:

Originally Posted by jayme

have you tried..

(Toggle Plain Text)

SNIP

I'm really hungry so not really into it as much, i hope you understand what i'm trying to say.

Do you even know what you're doing when you type code in? Your code doesn't even come close to compiling, so no I don't "understand what you're trying to say".

First off...

(Toggle Plain Text)

void print()
{
  ...
}printnum;

What is printnum? I know you can create instance members of classes like that, but never seen anyone do that with a function.

Also...

(Toggle Plain Text)

addClass();
if(addClass)

First you use addClass like a function and then you use it like a variable. Which is it?

I realize you're probably learning C++, but the best way to learn it is:

Read forums. [CHECK]
Participate in discussions. [CHECK]
Test your code before you post, instead of guessing [...]

Anyhow, to the original poster. The reason your print function isn't printing out everything is because you must set "i = 0" in the print function. You have a global variable (which is generally a bad idea) that is incremented up to loc, but it's never set back to the beginning.

There are other issues however. Department code can only be one character, because you've declared "department" to be 2 characters, but one of those characters is going to be occupied by \0 because you're using a char* string. You should probably stick to std::string if you're using C++, unless of course your professor does not allow it.

jayme · Jan 26th, 2006, 5:43 PM

Quote:

Do you even know what you're doing when you type code in? Your code doesn't even come close to compiling, so no I don't "understand what you're trying to say".

You don't have to be a dick about it. I said i wasn't into it, i'm not going to give him a complete answer. I was simply trying to point him in the right direction. You seemed to figure out what i was getting at by bringing up classes, so you did understand somewhat.

PS. And no, i don't have a clue what i'm doing when i type code in... but i still get it right more than half the time so it's ok.

Jason Isom · Jan 26th, 2006, 5:47 PM

Quote:

Originally Posted by jayme

You don't have to be a dick about it. I said i wasn't into it, i'm not going to give him a complete answer. I was simply trying to point him in the right direction. You seemed to figure out what i was getting at by bringing up classes, so you did understand somewhat.

I apologize. I definitely did not intend to come off as a dick. Sometimes I feel as though members just post code to increase their post count, but I guess the important thing is that all you were trying to do was to help the original poster.

Ooble · Jan 26th, 2006, 5:51 PM

Jason, you were kinda harsh, but I agree when you say that code should have been checked first. There's nothing worse than teaching a newbie the wrong thing - I know it confuses the heck out of me when people do that.

Jason Isom · Jan 26th, 2006, 5:59 PM

Here's some code of how I would do it. It's not perfect, but then again I haven't programmed C++ in years (mostly a C# guy). I think by placing the code for the functions in the class it will suggest to the compiler that it should be inlined, but the functions are so simple it shouldn't matter that much.

The output could probably be cleaner. Maybe use some \t or setw(...) to make some nice preformatted output.

(Toggle Plain Text)

#include <iostream>
#include <string>
#include <vector>

class Transcript{
public:		
	void print()
	{
		for(unsigned int i = 0; i < m_Classes.size(); i++)
		{
			std::cout << m_Classes[i].m_Department << " "
				<< m_Classes[i].m_CourseNumber << " "
				<< m_Classes[i].m_SemesterTaken << " "
				<< m_Classes[i].m_Grade << std::endl;
		}	  
		std::cout << std::endl;
	}

	void addClass()
	{
		ClassInfo temp;
		
		std::cout << "Please enter the department code: ";
		std::cin >> temp.m_Department;
		std::cout << "Please enter the course number: ";
		std::cin >> temp.m_CourseNumber;
		std::cout << "Please enter the semester: ";
		std::cin >> temp.m_SemesterTaken;
		std::cout << "Please enter the grade earned: ";
		std::cin >> temp.m_Grade;
		std::cout << std::endl;
		
		m_Classes.push_back(temp);
	}

private:	
	struct ClassInfo
	{
		std::string m_Department;
		int m_CourseNumber;
		std::string m_SemesterTaken;
		char m_Grade;
	};
	std::vector<ClassInfo> m_Classes;
};

int main()
{
	Transcript myTranscript;
	
	int option = -1;  
	while(option !=4)
	{
		std::cout << "Please make a selection: \n"
			<< "1. Add a new class. \n"
			<< "2. Print your current list of classes. \n"
			<< "3. Check your courses against the requirements. \n"
			<< "4. Quit \n"
			<< "Your selection: ";
			
		std::cin >> option;   
		std::cout << std::endl;

		switch(option)
		{
		case 1:
			myTranscript.addClass();
			break;
		case 2:
			myTranscript.print();
			break;
		case 3:
			// Add Functionality
			break;
		case 4:
			std::cout << "Quitting..." << std::endl;
			break;
		default:
			std::cout << "Error: Choose again." << std::endl << std::endl;
		}	
	} 
}

cwl157 · Jan 26th, 2006, 6:03 PM

ok i apologize. I should have made this clear in the beginning but i can't use classes to make this program. I can only use structs and subroutines.

The Dark · Jan 26th, 2006, 6:06 PM

Without rearranging your whole program as Jason did, the simple fix is that you have a global variable called i which is not being reset when you print. You don't need a globale variable here and I would certainly recommend against ever having a global variable called i.

Delete the global variable i and change your print loop to look something like:

(Toggle Plain Text)

  for (int i = 0; i < loc; i++)
  {
   cout << clInfo[i].department << "  "  
         << clInfo[i].courseNumber << "  " 
         << clInfo[i].semesterTaken << "  " 
         << clInfo[i].grade
         << endl;
    i++;

  }

The int declaration inside the for loop declares it as local to the for (depending on your compiler, it might also be available outside the for loop, but it is still local to the function).

Jason Isom · Jan 26th, 2006, 6:36 PM

Quote:

Originally Posted by cwl157

ok i apologize. I should have made this clear in the beginning but i can't use classes to make this program. I can only use structs and subroutines.

Can you use std::string? Or do you have to use char arrays? If you have to use char arrays, can department code be more than one character?

Because...

Quote:

Originally Posted by Jason Isom

Anyhow, to the original poster. The reason your print function isn't printing out everything is because you must set "i = 0" in the print function. You have a global variable (which is generally a bad idea) that is incremented up to loc, but it's never set back to the beginning.

There are other issues however. Department code can only be one character, because you've declared "department" to be 2 characters, but one of those characters is going to be occupied by \0 because you're using a char* string. You should probably stick to std::string if you're using C++, unless of course
your professor does not allow it.

You're using std::cin for input into a character array without any thought about how many characters a user will type. If they type more than 1 (because you're using char department[2]) it will actually cause a out of bounds error. When you std::cout the department, it will actually keep printing random stuff until it encounters a null-terminating character (\0). They occur often enough on disk that your program won't crash every single time, but you definitely should look into a version of getline. At least I think getline is what you're looking for.

Jan 26th, 2006, 4:20 PM	#1
cwl157 Professional Programmer Join Date: Feb 2005 Posts: 343 Rep Power: 4	simple program problem I have to write a program that prompts the user to enter a course by department course number semester taken and what the final grade was. Then the user has the option to print the courses entered or check the courses entered against the requirements. Right now i am working on entering the courses and printing the courses entered. I can enter and print courses fine the first time. However, if i try to enter 1 course and then say print that course out. Then i ask to add another course and print that it should print both courses however it only prints the second course entered. I'm very new to C++ i just have some java experience so any help would be very appreciated. Heres the code: (Toggle Plain Text) #include <iostream> #include <string.h> using namespace std; struct classInfo { char department[2]; int courseNumber; char semesterTaken[5]; char grade; }; struct classInfo clInfo[100]; int loc = 0; int i = 0; void print() { while(i < loc) { cout << clInfo[i].department << " " << clInfo[i].courseNumber << " " << clInfo[i].semesterTaken << " " << clInfo[i].grade << endl; i++; } cout << endl; } void addClass () { cout << "Please enter the department code: "; cin >> clInfo[loc].department; cout << "Please enter the course number: "; cin >> clInfo[loc].courseNumber; cout << "Please enter the semester: "; cin >> clInfo[loc].semesterTaken; cout << "Please enter the grade earned: "; cin >> clInfo[loc].grade; cout << endl; loc++; } int main() { int option; while(option !=4) { cout << "Please make a selection: \n" << "1. Add a new class. \n" << "2. Print your current list of classes. \n" << "3. Check your courses against the requirements. \n" << "4. Quit \n" << "Your selection: "; cin >> option; cout << endl; if(option == 1) addClass(); if(option == 2) print(); } return 0; } #include <iostream> #include <string.h> using namespace std; struct classInfo { char department[2]; int courseNumber; char semesterTaken[5]; char grade; }; struct classInfo clInfo[100]; int loc = 0; int i = 0; void print() { while(i < loc) { cout << clInfo[i].department << " " << clInfo[i].courseNumber << " " << clInfo[i].semesterTaken << " " << clInfo[i].grade << endl; i++; } cout << endl; } void addClass () { cout << "Please enter the department code: "; cin >> clInfo[loc].department; cout << "Please enter the course number: "; cin >> clInfo[loc].courseNumber; cout << "Please enter the semester: "; cin >> clInfo[loc].semesterTaken; cout << "Please enter the grade earned: "; cin >> clInfo[loc].grade; cout << endl; loc++; } int main() { int option; while(option !=4) { cout << "Please make a selection: \n" << "1. Add a new class. \n" << "2. Print your current list of classes. \n" << "3. Check your courses against the requirements. \n" << "4. Quit \n" << "Your selection: "; cin >> option; cout << endl; if(option == 1) addClass(); if(option == 2) print(); } return 0; }

Jan 26th, 2006, 5:51 PM	#6
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	Jason, you were kinda harsh, but I agree when you say that code should have been checked first. There's nothing worse than teaching a newbie the wrong thing - I know it confuses the heck out of me when people do that. __________________ Me :: You :: Them

Jan 26th, 2006, 5:59 PM	#7
Jason Isom Programmer Join Date: Dec 2005 Posts: 53 Rep Power: 3	Here's some code of how I would do it. It's not perfect, but then again I haven't programmed C++ in years (mostly a C# guy). I think by placing the code for the functions in the class it will suggest to the compiler that it should be inlined, but the functions are so simple it shouldn't matter that much. The output could probably be cleaner. Maybe use some \t or setw(...) to make some nice preformatted output. (Toggle Plain Text) #include <iostream> #include <string> #include <vector> class Transcript{ public: void print() { for(unsigned int i = 0; i < m_Classes.size(); i++) { std::cout << m_Classes[i].m_Department << " " << m_Classes[i].m_CourseNumber << " " << m_Classes[i].m_SemesterTaken << " " << m_Classes[i].m_Grade << std::endl; } std::cout << std::endl; } void addClass() { ClassInfo temp; std::cout << "Please enter the department code: "; std::cin >> temp.m_Department; std::cout << "Please enter the course number: "; std::cin >> temp.m_CourseNumber; std::cout << "Please enter the semester: "; std::cin >> temp.m_SemesterTaken; std::cout << "Please enter the grade earned: "; std::cin >> temp.m_Grade; std::cout << std::endl; m_Classes.push_back(temp); } private: struct ClassInfo { std::string m_Department; int m_CourseNumber; std::string m_SemesterTaken; char m_Grade; }; std::vector<ClassInfo> m_Classes; }; int main() { Transcript myTranscript; int option = -1; while(option !=4) { std::cout << "Please make a selection: \n" << "1. Add a new class. \n" << "2. Print your current list of classes. \n" << "3. Check your courses against the requirements. \n" << "4. Quit \n" << "Your selection: "; std::cin >> option; std::cout << std::endl; switch(option) { case 1: myTranscript.addClass(); break; case 2: myTranscript.print(); break; case 3: // Add Functionality break; case 4: std::cout << "Quitting..." << std::endl; break; default: std::cout << "Error: Choose again." << std::endl << std::endl; } } } #include <iostream> #include <string> #include <vector> class Transcript{ public: void print() { for(unsigned int i = 0; i < m_Classes.size(); i++) { std::cout << m_Classes[i].m_Department << " " << m_Classes[i].m_CourseNumber << " " << m_Classes[i].m_SemesterTaken << " " << m_Classes[i].m_Grade << std::endl; } std::cout << std::endl; } void addClass() { ClassInfo temp; std::cout << "Please enter the department code: "; std::cin >> temp.m_Department; std::cout << "Please enter the course number: "; std::cin >> temp.m_CourseNumber; std::cout << "Please enter the semester: "; std::cin >> temp.m_SemesterTaken; std::cout << "Please enter the grade earned: "; std::cin >> temp.m_Grade; std::cout << std::endl; m_Classes.push_back(temp); } private: struct ClassInfo { std::string m_Department; int m_CourseNumber; std::string m_SemesterTaken; char m_Grade; }; std::vector<ClassInfo> m_Classes; }; int main() { Transcript myTranscript; int option = -1; while(option !=4) { std::cout << "Please make a selection: \n" << "1. Add a new class. \n" << "2. Print your current list of classes. \n" << "3. Check your courses against the requirements. \n" << "4. Quit \n" << "Your selection: "; std::cin >> option; std::cout << std::endl; switch(option) { case 1: myTranscript.addClass(); break; case 2: myTranscript.print(); break; case 3: // Add Functionality break; case 4: std::cout << "Quitting..." << std::endl; break; default: std::cout << "Error: Choose again." << std::endl << std::endl; } } }

Jan 26th, 2006, 6:06 PM	#9
The Dark Expert Programmer Join Date: Jun 2005 Posts: 850 Rep Power: 4	Without rearranging your whole program as Jason did, the simple fix is that you have a global variable called i which is not being reset when you print. You don't need a globale variable here and I would certainly recommend against ever having a global variable called i. Delete the global variable i and change your print loop to look something like: (Toggle Plain Text) for (int i = 0; i < loc; i++) { cout << clInfo[i].department << " " << clInfo[i].courseNumber << " " << clInfo[i].semesterTaken << " " << clInfo[i].grade << endl; i++; } for (int i = 0; i < loc; i++) { cout << clInfo[i].department << " " << clInfo[i].courseNumber << " " << clInfo[i].semesterTaken << " " << clInfo[i].grade << endl; i++; } The int declaration inside the for loop declares it as local to the for (depending on your compiler, it might also be available outside the for loop, but it is still local to the function).

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Jan 26th, 2006, 6:03 PM	#8
cwl157 Professional Programmer Join Date: Feb 2005 Posts: 343 Rep Power: 4	ok i apologize. I should have made this clear in the beginning but i can't use classes to make this program. I can only use structs and subroutines.

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Programming Forums > Application Development > C++

simple program problem