3 arguments expected, 0 provided

[ape1]

trying to print a concatenation through a vector of objects(my students class)

//Header File

#ifndef CLASSES_H
#define CLASSES_H

#include <iostream>
#include <string>

using namespace std;

class Students
{

	public:
	
		//constructor
		Students();
		
		//overload constructor
		Students(int, string, string);
		
		//destructor
		~Students();
		
		//accessors
		string getId(string, string, string);
		
		string getfName();
		
		string getlName();
		
		//mutators
		void setId(int);
		
		void setfName(string);
		
		void setlName(string);
		
	protected:
	
		int id;
		
	private:
	
		string fName;
		string lName;
};

//Classes.cpp - prototype file

#include "Classes.h"

Students::Students()
{
	int newId = 0;
};

Students::Students(int id, string fName, string lName)
{
	int newId = id;
	string newfName = fName;
	string newlName = lName;
};

Students::~Students()
{

};

string Students::getId(string newId, string newfName, string newlName)
{
	string newID = newId + ", ";
	newID = newID + newfName;
	newID = newID + ", ";
	newID = newID + newlName;
	
	return newID;
};

string Students::getfName()
{
	return fName;
};

string Students::getlName()
{
	return lName;
};

void Students::setId(int id)
{
	int newId = id;
	/*string newID = id + ", ";
	newID = newID + fName;
	newID = newID + ", ";
	newID = newID + lName;*/
};

void Students::setfName(string fName)
{
	string newfName = fName;
};

void Students::setlName(string lName)
{
	string newlName = lName;
};
//main
#include <iostream>
#include <string>
#include <vector>
#include "Classes.h"

using namespace std;

//fills in class vector
void fillClass(vector<Students>&);

//prints the info of students
void printClass(vector<Students>&);

int main()
{

	vector<Students> class1;
	
	int id;
	string fName;
	string lName;
	string choice;
	cin >> choice;
	
	while(choice != "quit")
	{
		cout << "tables> ";
		
		if(choice == "students")
		{
			string operation;
			cin >> operation;
			
			if(operation == "add")
			{
				fillClass(class1);
			};
			if(operation == "display")
			{
				printClass(class1);
			};
		};	
	return 0;	
	};
};	

void fillClass(vector<Students>& Class1)
{
	int id;
	string fName;
	string lName;
	
	cin >> id;
	cin >> fName;
	cin >> lName;
	
	Students newStudents(id, fName, lName);
	Class1.push_back(newStudents);
};

void printClass(vector<Students>& Class1)
{
	unsigned int size = Class1.size();
	
	for(unsigned int i = 0; i < size; i++)
	{
		cout << "( )" << Class1[i].getId() << endl;
		cout << endl;
	}
};

[MiiNiPaa]

string getId(string, string, string);
//...
cout << "( )" << Class1[i].getId() << endl;

You forgot to pass 3 strings as promised.

[ape1]

so,

.....getId(newID, newfName, newlName) << endl; ?

[mutexe]

whilst minipaa has answered your question, I don't think your design is right. Neither is the constructor implementation:

Students::Students(int id, string fName, string lName)
{
	int newId = id;
	string newfName = fName;
	string newlName = lName;
};

you pass in variables into a constructor to store them with your object, but here you are just assigning them to local variables (which will be destroyed when it goes out of scope).
if you assign these to member variables then you would not have to pass anything into your getID() method.

you've correctly declared these in your class:

private:
	
		string fName;
		string lName;

but don't set them correctly in your constructor.

[ape1]

ok so i should get rid of all the changing around of the various variable and stick with the original 3(id, fname, lname)

where would i would to implement the concatenation?
do i create another function?
do i do it inside of a object in the class already?

Im new to vectors and im not fantastic with passing of thngs

[mutexe]

keep this the same:

	protected:
	
		int id;
		
	private:
	
		string fName;
		string lName;

in your class definition.
and change your ctor to something like this:

Students::Students(int newId, string newFname, string newLName)
{
	id= newId;
	fName= newFname;
	Name= newLName;
        // now you have saved the variables away in your class variable
};

then you can write a concantenate function in your Students class, and call it where you want to.

edit:
and as a side note, I'd rename your class to Student, as each object is information for just one student. But I wouldn't worry about that too much.

[ape1]

Thank Yall for the help!
I think I will be able to get it to work properly now. :)