"Undefined reference to..." OOP. C++

[MisterWhite]

Basically i just started learning about Object-Oriented Programming and started off with few basic tasks.

I've triple checked everything with an example i had from youtube and all seems to be fine, but i still get an error :
"undefined reference to `SQUARE::SQUARE(int, int, double)"

I have my code in three files:

Header:
 

#include <string>
#include <iostream>

using namespace std;
#ifndef SQUARE_H
#define SQUARE_H

class SQUARE
{
public:

    //Default constructor
    SQUARE(); // nullifies the values
    //Overload constructor
    SQUARE(int,int,double);
    // will asign values to x,y, length
    ~SQUARE();
    // Destructor

    int getNewX() const;
    int getNewY() const;
    double getNewLength() const;
        // get - returns all values

private:
    int newX,newY;
    double newLength;
};
#endif // SQUARE_H_INCLUDED

The one where you define functions:

#include "Square.h"

SQUARE::SQUARE()
{
    newX=0;
    newY=0;
    newLength=0.0;
}

SQUARE::SQUARE(int X, int Y, double Length)
{
    newX=X;
    newY=Y;
    newLength=Length;
}
SQUARE::~SQUARE()
{

}
//**************************************
int SQUARE::getNewX() const
{
    return newX;
}
int SQUARE::getNewY() const
{
    return newY;
}
double SQUARE::getNewLength const
{
    return newLength;
}
//****************************************

And the main:

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

#include "Square.h"

int main()
{
    int X=0,Y=0;
    double Length=7.0;
    cin>>X;
    SQUARE test(X,Y,Length);// error occurs on declaration

    cout<<test.getNewX(); 
    return 0;
}

Sorry for the long post :P,
maybe someone will find my mistake.
All files are added to the project.

[SysVoid]

I've not really done much C++, but this could be an issue for future:

double SQUARE::getNewLength const
{
    return newLength;
}

Don't you need ()'s there?

[MisterWhite]

Just now, SysVoid said:

I've not really done much C++, but this could be an issue for future:

double SQUARE::getNewLength const
{
    return newLength;
}

Don't you need ()'s there?

I am returning a variable so i don't think so.

[SysVoid]

1 minute ago, MisterWhite said:

I am returning a variable so i don't think so.

OK

 

Does C++ have default variables for methods? Maybe you could try that instead of overloading?

 

Also, does anything happen if you change the order of those constructors?

[fizzlesticks]

2 minutes ago, MisterWhite said:

I am returning a variable so i don't think so.

You do need the ().

[MisterWhite]

Just now, SysVoid said:

OK

 

Does C++ have default variables for methods? Maybe you could try that instead of overloading?

As my native language is not English and i just started OOP i do not understand what do you mean :). I follow an example from the interweb

[SysVoid]

1 minute ago, MisterWhite said:

As my native language is not English and i just started OOP i do not understand what do you mean :). I follow an example from the interweb

Can you do:

 

SQUARE();
SQUARE(int, int, double);

 

SQUARE::SQUARE(int X = 0.0, int Y = 0.0, double Length = 0.0)
{
    // stuff stuff
}

 

 

[MisterWhite]

Just now, SysVoid said:

 

 

SQUARE::SQUARE(int X = 0.0, int Y = 0.0, double Length = 0.0)
{
    // stuff stuff
}

 

Maybe, i dont know xd. but my problem is not with efficiency  or overloading, just that it "does not see" my class

[SysVoid]

Just now, MisterWhite said:

Maybe, i dont know xd. but my problem is not with efficiency  or overloading, just that it "does not see" my class

Try putting your #include "Square.h" before using namespace std;

[MisterWhite]

4 minutes ago, fizzlesticks said:

You do need the ().

Do I?

 

https://www. youtube.com/watch?v=b9wialxvcVA

Here i don't.

http://www.learncpp.com/cpp-tutorial/85-constructors/

Here also

 

[MisterWhite]

Just now, SysVoid said:

Try putting your #include "Square.h" before using namespace std;

Still the same.

I attached all the files if someone  tries to go through them.

Class - Shapes.cbp

main.cpp

Square.cpp

Square.h

[fizzlesticks]

1 minute ago, MisterWhite said:

Do I?

 

https://www. youtube.com/watch?v=b9wialxvcVA

Here i don't.

http://www.learncpp.com/cpp-tutorial/85-constructors/

Here also

 

Is "Fraction frac; // Since no arguments, calls Fraction() default constructor " the part you're talking about?

If so, that's only when calling the default constructor, you always need parenthesis when defining a function.

 

What compiler are you using and how are you trying to compile your code?

 

[MisterWhite]

Just now, fizzlesticks said:

Is "Fraction frac; // Since no arguments, calls Fraction() default constructor " the part you're talking about?

If so, that's only when calling the default constructor, you always need parenthesis when defining a function.

 

What compiler are you using and how are you trying to compile your code?

 

Using Code::Blocks, compiler: mingw somthing. I just press F9 or Buil & Run.
Btw are you talking about this:
 

int SQUARE::getNewY() const
{
    return newY; // you mean this should be return newY();?
}

 

[SysVoid]

 

5 minutes ago, MisterWhite said:

Using Code::Blocks, compiler: mingw somthing. I just press F9 or Buil & Run.
Btw are you talking about this:
 

int SQUARE::getNewY() const
{
    return newY; // you mean this should be return newY();?
}

 

34 minutes ago, MisterWhite said:

I am returning a variable so i don't think so.

 

[fizzlesticks]

3 minutes ago, MisterWhite said:

Btw are you talking about this:
 

int SQUARE::getNewY() const
{
    return newY; // you mean this should be return newY();?
}

 

No, that's fine since you're just returning a variable.

 

You're missing the () on the line

double SQUARE::getNewLength const

should be

double SQUARE::getNewLength() const

 

[Nineshadow]

Your example works for me.

 

Also this works for me :

struct square
{
public:
    square():_x(0),_y(0),_length(0) {}
    square(int x , int y , int length) : _x(x) , _y(y) , _length(length) {}
    int getX() const
    {
        return _x;
    }
    int getY() const
    {
        return _y;
    }
    double getLength() const
    {
        return _length;
    }
private:
    int _x,_y;
    double _length;
};

 

[MisterWhite]

Just now, fizzlesticks said:

No, that's fine since you're just returning a variable.

 

You're missing the () on the line

double SQUARE::getNewLength const

should be

double SQUARE::getNewLength() const

 

Yea, that's my mistake, though the program did not go that far as it encountered with my class being undefined

[SysVoid]

4 minutes ago, MisterWhite said:

Yea, that's my mistake, though the program did not go that far as it encountered with my class being undefined

Called it!

[Nineshadow]

3 minutes ago, MisterWhite said:

Yea, that's my mistake, though the program did not go that far as it encountered with my class being undefined

It works for me. Of course , with that small correction.

[Nineshadow]

I reckon you haven't linked your class properly. Are you using any IDE? One should have done that for you. Otherwise, you need to do it yourself.

[fizzlesticks]

I tried the project files you uploaded and the problem is that code::blocks isn't compiling the Square.cpp file. I don't know enough about code::blocks to figure out what's wrong but making a new project and copying the files over fixed it for me.

[MisterWhite]

Just now, Nineshadow said:

I reckon you haven't linked your class properly. Are you using any IDE? One should have done that for you. Otherwise, you need to do it yourself.

Yea Code::blocks. I have added all my files. i believe everything is linked.
keep in mind just starting to swim in this ocean

Class - Shapes.cbp

main.cpp

Square.cpp

Square.h

 

i will check LTT tomorrow.

[Nineshadow]

Just now, MisterWhite said:

 

Using g++ , you basically need to compile both cpps into object files.

g++ -c main.cpp

g++ -c SQUARE.cpp

Then compile your program from the resulting object files :

g++ -o square.exe main.o SQUARE.o

Of course, assuming that all the files are in the same directory.

[Nineshadow]

1 minute ago, MisterWhite said:

Yea Code::blocks. I have added all my files. i believe everything is linked.
keep in mind just starting to swim in this ocean

Class - Shapes.cbp

main.cpp

Square.cpp

Square.h

Ah  , if you are using Code::blocks just make sure you also compile Square.cpp , not just main.cpp .

[MisterWhite]

16 hours ago, Nineshadow said:

Ah  , if you are using Code::blocks just make sure you also compile Square.cpp , not just main.cpp .

Thing is, this is not my first time using several files when working with OOP and it is the first time i get this error.

EDIT: oh, wow, removed all files from the project, added them and everything works... Thanks for the help though