simple class

[empror9]

hello,

i'm still beigner for classes in c++

now i'm trying to write a simple university system which is to create student,subject...etc

now i want to create on;y new subject and please see my code

#include<iostream>
using namespace std;

class subject
{
	string code;
 public:
	void create_code();
};

class student
{
	string name;
 public:
	void create_student();
};

int main()
{

create_code();
	return 0;
}

void subject::create_code()
{
	cout <<"Creat a new subject: " <<endl;
	cin >> code;
}

void student::create_student()
{
	cout <<"Creat a new student: " <<endl;
	cin >> name;
}

my problem is in the main function and i want to call the member function for the class subject.

please notice that i'm still beigner

waiting for you

[shredded]

Hi

first you need to create an instance of your class,
and then call the method of your new object

int     main()
{
        subject*   sub = new subject();

        sub->create_code();
}

Hope this helps
Shredded

[empror9]

hi there,

i tried your code but it doesn't work

is it like this?

int main()
{
subject*sub = new subject();

    sub->create_code();
create_code();
	return 0;
}

[shredded]

Hi again,

Yeah sorry I didnt test the code what is missing is

#include <string>

at top of file

I would also move code & name in class decleration under either public or private
eg.

class subject
{
	
 public:

	void create_code();

private:
	string code;
};

Edit: Keep main as in my first post

It should work this time
Shredded

[ne555]

except that there is no need to work with pointers and dynamic allocation.
And student::create_student or subject::create_code() don't create new instances, but set the state of the object

[Blessman11]

you guys might be confusing him, I think for a beginner he is trying to use the dot operator.

any basics to call your functions or objects:

WRITE CLASS NAME CLASS OBJECT-CREATED NAME;

int main()
{
 subject myobject;

//to access members of the class
//write myobject then .(dot)             call what ever is inside your class
//its would be the same as usual for any public objects only
//just remember your object name and the dot operator 

myobject. create_code();

return 0;
}

[hasula]

hi, i'm beginner too, i dont understand what your codes purpose, but to make it compiled i do a little modification , it's compiled and run well

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

class subject
{
	string code;
 	public:
	void create_code();
};

void subject::create_code()
{
	cout <<"Creat a new subject: " <<endl;
	cin >> code;
}


//------------------------
class student
{
	string name;
 	public:
	void create_student();
};
void student::create_student()
{
	cout <<"Creat a new student: " <<endl;
	cin >> name;
}
//--------------------
int main()
{
	subject yoursubject;
	student yourstudent;
	yoursubject.create_code();
	yourstudent.create_student();
	return 0;
}

with different class your subject and student are sparated , soo i choose this way to make it simpler, like this :

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


//------------------------
class student
{	
 	public:
 	string code;
	string name;
	void create_student()
		{
			cout <<"Creat a new student: ";
			cin >> name;
		};
	void create_code()
		{
		cout <<"Creat a new subject: " ;
		cin >> code;
	}
}

;
//--------------------
int main()
{
	int counter;
	cout<<"\nHow many student do you want to add ? : ";cin>>counter;
	
	student yourstudent[counter];
	for(int i=0;i<counter;i++)
		{
			yourstudent[i].create_student();
			yourstudent[i].create_code();
			system("cls");
		}
	system("cls");
	cout<<"added student is : ";
	for(int i=0;i<counter;i++)
		{
			cout<<"\n["<<i<<"] "<<yourstudent[i].code;
			cout<<"   "<<yourstudent[i].name;
		}
	cout<<"\n\n\n";
	system("pause");
	return 0;
}

hope this help, if you see something wrong in this code please notice me at [e-mail] in facebook, sorry for my bad english

[empror9]

thanks for all you guys

it helps me a lot, but now i have a question

after i creating subject and students, then i want to list all the subject or list all the student

or maybe list all the subejects for a specific stuednt

to solve this, shloud i use vector? or just class?

[empror9]

waiting

[hasula]

on modified code above, you will have data packed in an array , look to
student yourstudent[counter];
how many your students are depending to your input assigned to counter.
its like

yourstudent[1]
yourstudent[2]
yourstudent[etc]

my second sample above answer your problem, after creating subject it shows the list, and if you like to see specific student you can use

if(student[i].name == "yourchoice")
{
cout>>endl>>student[i].name;
};

simple isnt it ?