Trouble with constructors and destructors in classes

Code:

Im working on a a circle class program in which I have to find the diameter and area of the circle. I have divided the program into 3 files, 1 main.cpp 1 circle.cpp and 1 circle.h
My code produces and error:

1>main_Circle.obj : error LNK2019: unresolved external symbol "public: __thiscall Circle::~Circle(void)" (??1Circle@@QAE@XZ) referenced in function _main
1>main_Circle.obj : error LNK2019: unresolved external symbol "public: __thiscall Circle::Circle(double)" (??0Circle@@QAE@N@Z) referenced in function _main
1>C:\Users\RKLO\documents\visual studio 2010\Projects\Rectangle class2\Debug\Rectangle class2.exe : fatal error LNK1120: 2 unresolved externals


Here is my code


//Cirlcle.h
#pragma once
//Circle class declaration

class Circle
{
	private:
		double radius;
	
	public:

	Circle(double=0);
	Circle (const Circle &);
	~Circle();
	
	void setRadius(double);
	double getRadius()const;
	double getDiameter()const;
	double getArea()const;
};

//Circle.cpp

//Implementation file for Circle class

#include "Circle.h"//Needed for the rectangle class
#include<iostream>//Needed for the cout
#include<cstdlib>//Needed for the exit function
using namespace std;

//sets the value of the member radius


void Circle::setRadius(double r)
{
	if (r>=0) {
		radius=r;
	}
	else {
		cout << "Invalid radius\n";
		exit(EXIT_FAILURE);
	}
}

//returns the value mamber of the variable radius
double Circle::getRadius()const
{
	return radius;
}
//returns the value member of the variable Diameter
double Circle:: getDiameter()const
{
	return 2*radius;
}
//get area returns the pruduct times pi*radius^2

double Circle:: getArea()const
{
	return 3.1416*radius*radius;
}

//main_Circle.cpp

#include <iostream>
#include "Circle.h"//Neede for the rectangle class
using namespace std;

int main()
{
	Circle box;
	double radiusCircle;//Local variable for radius
	cout<<"This program will calculate the area of a\n" ;
	cout << "circle. What is the radius? ";
	cin>>radiusCircle;
	
	box.setRadius(radiusCircle);
	
	cout << "Here is the circle's data: ";
	cout << "Radius: "<<box.getRadius()<<endl;
	cout << "Diameter "<<box.getDiameter()<<endl;
	cout << "The Area of the Circle is "<<box.getArea()<<endl;
	
	return 0;
}


Any help will be really appreciated
I have uploaded the three files for your convenience.

You didn't implement the constructor and destructor.

Don't put your whole post in code tags, only the part which contains actual code.

To re-ellaborate on what Xupicor is saying... You didn't write a default constructor.

Code:

Circle() { };

Once you write a constructor C++ stops making a default for you. Since your code in main calls

Code:

Circle box;  //Doesn't exist no Circle() function in class Circle (You wrote Circle(double=0))

you get an error. You have to write Circle(double=0) as Circle() to get your code to work. Plus you never defined Circle(const Circle &) or Circle(double=0) anyways so yeah, they don't work if they have no definition :P

Simply put, change Circle(double=0) to Circle() { } and define Circle(const Circle &) in the Circle.cpp file....

Thanks guys I fixed my program it worked really nice.

Code:

Here is my fixed code for the benefit of anyone:

//Circle.h

#pragma once
const double pi=3.1416;
class Circle 
{
private:
	double diameter,area,radius;
public:

	Circle(double=0.0);
	Circle(const Circle&);
	~Circle();
	void SetDiameter(double);
	void setArea(double);
	void setRadius(double a);
	double getDiameter()const;
	double getRadius()const;
	double getArea()const;
	void printData()const;

};//end class

//Circle.cpp
#include "Circle.h" //needed for the class
#include<iostream>//needed for the cout
#include<cstdlib>
using namespace std;

void Circle::setRadius(double r)
{
if(r>0){
	radius=r;
}
else{
	cout<<"Invalid Radius\n";
	exit(EXIT_FAILURE);
}

}//end set radio
void Circle::setArea(double a)
{
	area =a;
}//end set area

void Circle::SetDiameter(double d)
{
	diameter=d;
}//end set diameter

double Circle::getRadius()const
{
	return radius;
}//end getRadius

double Circle::getArea()const
{
	return pi*radius*radius;
}//end getArea

double Circle::getDiameter()const
{
	return 2*radius;
}//end getDiameter

void Circle::printData()const
{
	cout<<"Radius: "<<getRadius()<<endl;
	cout<<"Diameter: "<<getDiameter()<<endl;
	cout<<"Area: "<<getArea()<<endl;
	cout<<endl;
}//end printData

Circle::Circle(double)
{}//end constructor

Circle::Circle(const Circle & instance)
{}//end constructor

Circle::~Circle()
{}//end destructor

//main_circle.cpp

#include<iostream>
#include<cstdio>
#include<cctype>
using namespace std;
#include "circle.h"

int main()
{
	Circle box1,box2;
	char e;
	double r,CirArea,CirDiam;
		
	do{
	cout<<"This program will calculate the area of a \n";
	cout<<"Circle; What is the radius?"<<endl;
	cin>>r;
	box1.setRadius(r);
	box2.setRadius(r);
	box2.printData();
	cout<<endl;
	
cout<<" The Area of the Cirlce is: "<< box1.getArea() <<endl<<endl;
cout<<"Type any non-digit character to exit"<<endl;
cout<<"Press any number to continue and then hit Enter"<<endl;
cin>>e;
	
	//box1.getArea();
	//box1.getDiameter();


	cout<<"This program will calculate the area of a \n";
	cout<<"Circle; What is the radius?"<<endl;
	cin>>r;

	box2.setRadius(r);
	box2.printData();
	cout<<endl;

cout<<"Type a non-numeric value to exit"<<endl;
cout<<"Press any number to continue and then hit Enter"<<endl;
	cin>>e;	}while(isdigit(e));

	system("pause");
	return 0;
}//end main

I uploaded the files for the benefit of the user.

<sigh>

So you fixed it, great. But...

Originally Posted by hk_mp5kpdw

Don't put your whole post in code tags, only the part which contains actual code.