What's is wrong with this piece of c++ code? I am practising object oriented programming.

Question

#include <iostream>
#include <math.h>

using namespace std;

class Point{
public:
    Point(int xx, int yy);
    ~Point();

    int getX();
    int getY();
    void setX(int xx){ x = xx; }
    void setY(int yy){ y = yy;}

private:
    int x;
    int y;

};

Point::Point(int xx, int yy)
{
    x = xx;
    y = yy;
}

Point::~Point()
{
}

int Point::getX()
{
    return x;
}


int Point::getY()
{
    return y;
}

class Line
{
public:
    Line(Point one, Point two);
    ~Line();
    float length();

private:
    Point a;
    Point b;
};

Line::Line(Point one, Point two)
{
    a.setX = one.getX;
    a.setY = one.getY;
    b.setX = two.getX;
    b.setY = two.getY;
}

float Line::length()
{
    int x1,y1,x2,y2;
    float linelength;

    x1 = a.getX;
    y1 = a.getY;
    x2 = b.getX;
    y2 = b.getY;

    linelength = ((x2-x1)*(x2-x1)) + ((y2-y1)*(y2-y1));
    linelength = sqrtf(linelength);

    return linelength;
}

int main()
{
    Point mine(1,1);
    Point yours(2,2);

    Line ours(mine, yours);

    cout << Line.linelength();

    return 0;
}

Answer 1

One thing is that the line

cout << Line.linelength();

Should be

cout << ours.length();

Answer 2

Your question isn't clear. You mean it doesn't compile?

try calling functions properly ie

x1 = a.getX();

instead of

x1 = a.getX;

and

a.setX(one.getX());

instead of

a.setX = one.getX;

but there is probably more wrong...

Answer 3

a.setX = one.getX;
a.setY = one.getY;
b.setX = two.getX;
b.setY = two.getY;

setX and getX are functions, not variables. Therefore, you need to use them as such:

a.setX(one.getX());

In the future for getting help on here, you should give a bit more information on what is wrong with your code: what compiler errors are you getting? what is not working? what are you having issues with?

Answer 4

I've been having a little play with this, and I was wondering why...

Line(const Point &one, const Point &two) : a(one), b(two) {};

is fine, but

Line(const Point &one, const Point &two);

then (later)

Line::Line(const Point &one, const Point &two)
{
    a = one;
    b = two;
}

gets...

frag.cpp: In constructor ‘Line::Line(const Point&, const Point&)’:
frag.cpp:57: error: no matching function for call to ‘Point::Point()’
frag.cpp:24: note: candidates are: Point::Point(int, int)
frag.cpp:8: note:                 Point::Point(const Point&)
frag.cpp:57: error: no matching function for call to ‘Point::Point()’
frag.cpp:24: note: candidates are: Point::Point(int, int)
frag.cpp:8: note:                 Point::Point(const Point&)

Anyone any idea why?