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Program crashing when initialized

puffybear123 (12)
Hi, I just finished coding a program that is based on polymorphism and inheritance but when I ran the program it crashed? I do not know what is the cause of the program crashing.

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

class Shape{
      float density;
      string *name;
      public:
             Shape(string title, float n)
             {
                          *name = title;
                          density = n;
             }
             virtual float dimension()=0;
             string getName(void){return *name;}
             float getDensity(void){return density;}
             virtual void getColor()=0;
             };
             
class Rectangle:public Shape{
      
      public:
             float length;
             float width;
             string rectColor;
             Rectangle(float le, float wi, string co, float de, string tye)
                             :Shape(tye, de)
                             {
                                        length = le;
                                        width = wi;
                                        rectColor = co;
                             }
                             void getColor(void)
                             {
                                  cout<<"Color : " <<rectColor;
                             }
                             float dimension(void)
                             {
                                   float t;
                                   t=length*width;
                                   return t;
                             }
                             };
class Cube: public Rectangle{
      float height;
      public:
             Cube(float len, float wid, float hei, string colo, float dens, string typ)
                        :Rectangle(len,wid,colo,dens,typ)
                        {
                            height = hei;
                        }
                        float dimenstion(void)
                        {
                              float k;
                              k = height*width*length;
                        }
                        };
       void find_Mass(Shape *Sobj_ref)
       {
                cout<<"Dimension : " <<Sobj_ref->dimension();
                cout<<"Density : " <<Sobj_ref->getDensity();
       }
 int main()
 {
     Shape*n[4];
     n[0]=new Rectangle(30,40,"Blue",0.34,"Rectangle A");
     n[1]=new Cube(10,20,5,"Green",1.5,"Cube 1");
     n[2]=new Rectangle(70,9,"Yellow",2.1,"Rectangle B");
     n[3]=new Cube(33,5,15,"Black",0.5,"Cube 2");
     for (int i=0; i<=3; i++)
     find_Mass(n[i]);
     system("PAUSE");
 }
Last edited on
Ispil (788)
Your dimension function for Cube doesn't actually return anything, despite supposedly returning a float. You then try to output it.
puffybear123 (12)
How would I fix this?
Zhuge (4664)
Return something from the function.
Ispil (788)
k would probably be the best bet.
puffybear123 (12)
After I added "return k;" to the coding the program still crashed. :(

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

class Shape{
      float density;
      string *name;
      public:
             Shape(string title, float n)
             {
                          *name = title;
                          density = n;
             }
             virtual float dimension()=0;
             string getName(void){return *name;}
             float getDensity(void){return density;}
             virtual void getColor()=0;
             };
             
class Rectangle:public Shape{
      
      public:
             float length;
             float width;
             string rectColor;
             Rectangle(float le, float wi, string co, float de, string tye)
                             :Shape(tye, de)
                             {
                                        length = le;
                                        width = wi;
                                        rectColor = co;
                             }
                             void getColor(void)
                             {
                                  cout<<"Color : " <<rectColor;
                             }
                             float dimension(void)
                             {
                                   float t;
                                   t=length*width;
                                   return t;
                             }
                             };
class Cube: public Rectangle{
      float height;
      public:
             Cube(float len, float wid, float hei, string colo, float dens, string typ)
                        :Rectangle(len,wid,colo,dens,typ)
                        {
                            height = hei;
                        }
                        float dimenstion(void)
                        {
                              float k;
                              k = height*width*length;
                              return k;
                        }
                        };
       void find_Mass(Shape *Sobj_ref)
       {
                cout<<"Dimension : " <<Sobj_ref->dimension();
                cout<<"Density : " <<Sobj_ref->getDensity();
       }
 int main()
 {
     Shape*n[4];
     n[0]=new Rectangle(30,40,"Blue",0.34,"Rectangle A");
     n[1]=new Cube(10,20,5,"Green",1.5,"Cube 1");
     n[2]=new Rectangle(70,9,"Yellow",2.1,"Rectangle B");
     n[3]=new Cube(33,5,15,"Black",0.5,"Cube 2");
     for (int i=0; i<=3; i++)
     find_Mass(n[i]);
     system("PAUSE");
 }
Ganado (6809)
Didn't look through the most of the program but you should realize you are misspelling your function at line 52. I'm guessing that's messing up your function call in find_Mass.
Last edited on
puffybear123 (12)
Oh haha yes it should've been dimensions but it is still crashing sadly.
Ganado (6809)
It's crashing when you do *name = title; in your Shape constructor. You're dereferencing an uninitialized pointer.

Why not just use a string object directly instead of a pointer to one?
Edit: Going off that... change your Shape to this
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class Shape{
      float density;
      string name;
      public:
             Shape(string title, float n)
             {
                          name = title;
                          density = n;
             }
             virtual float dimension()=0;
             string getName(void){return name;}
             float getDensity(void){return density;}
             virtual void getColor()=0;
};


Works fine for me now.
Last edited on
puffybear123 (12)
Yes it did work after removing the * from the shape constructor! Thank you Ganado and everyone else for the help! Here is the finished coding that displays the dimension, density, color and name when it is run.

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

class Shape{
      float density;
      string name;
      public:
             Shape(string title, float n)
             {
                          name = title;
                          density = n;
             }
             virtual float dimension()=0;
             string getName(void){return name;}
             float getDensity(void){return density;}
             virtual string getColor()=0;
             };
             
class Rectangle:public Shape{
      
      public:
             float length;
             float width;
             string rectColor;
             Rectangle(float le, float wi, string co, float de, string tye)
                             :Shape(tye, de)
                             {
                                        length = le;
                                        width = wi;
                                        rectColor = co;
                             }
                             string getColor(void)
                             {
                                    string r;
                                    r = rectColor;
                                    return r;
                             }
                             float dimension(void)
                             {
                                   float t;
                                   t=length*width;
                                   return t;
                             }
                             };
class Cube: public Rectangle{
      float height;
      public:
             Cube(float len, float wid, float hei, string colo, float dens, string typ)
                        :Rectangle(len,wid,colo,dens,typ)
                        {
                            height = hei;
                        }
                        float dimension(void)
                        {
                              float k;
                              k = height*width*length;
                              return k;
                        }
                        };
       void find_Mass(Shape *Sobj_ref)
       {
                cout<<"Name : " <<Sobj_ref->getName()<<endl;
                cout<<"Color : "<<Sobj_ref->getColor()<<endl;
                cout<<"Dimension : " <<Sobj_ref->dimension()<<endl;
                cout<<"Density : " <<Sobj_ref->getDensity()<<endl;
                
       }
 int main()
 {
     Shape*n[4];
     n[0]=new Rectangle(30,40,"Blue",0.34,"Rectangle A");
     n[1]=new Cube(10,20,5,"Green",1.5,"Cube 1");
     n[2]=new Rectangle(70,9,"Yellow",2.1,"Rectangle B");
     n[3]=new Cube(33,5,15,"Black",0.5,"Cube 2");
     for (int i=0; i<=3; i++)
     find_Mass(n[i]);
     system("PAUSE");
 }
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