segment fault with the program

I am receiving segment fault with this program

Code:

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#include <iostream>
#include <new>
#include <cstdlib>

using namespace std;

class ar
{
        int *p;
        int size;
        public:
        ar(int sz){
                cout<<"Initializing array in Constructor\n";
                try {
                        p = new int[sz];
                }
                catch(bad_alloc xa){
                cout <<"Allocation Failure\n";
                exit(EXIT_FAILURE);       
                }
        }
        ar (const ar &a);
        ~ar(){cout << "Destructor is called\n";delete []p;}
        void set_val(int i,int j){if(i>0&&i<size) p[i]=j; }
        void get_val(int i){cout<<"Val is :"<<p[i];cout<<"\t";}
};


ar::ar(const ar &a)
{
        int i;
        try
        {
                p = new int[a.size];
        }
        catch(bad_alloc sp)
        {
                cout<<"Allocation Failure\n";
                exit(EXIT_FAILURE);
        }
        for (i=0;i<a.size;i++) p[i]=a.p[i];
}

int main()
{
        ar a(5),b(5);
       
        b=a;       

        for(int i=0;i<5;i++)
                a.set_val(i,i);       
       
        b.set_val(2,3);         
        b.set_val(3,63);         
        b.set_val(4,983);         

        for(int i=0;i<5;i++)
                a.get_val(i);       
        cout<<"\n============ Copy Constructor goes here==============\n"  ;
        ar c(b);       
       
        for(int i=0;i<5;i++)
                c.set_val(i,i);       
       
        //c.set_val(2,3);         
        //c.set_val(3,63);         
        //c.set_val(4,983);         

        for(int i=0;i<5;i++)
                a.get_val(i);
        return 0;
}

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1. I am getting segment fault after the following statement
cout<<"\n============ Copy Constructor goes here==============\n" ;

Thanks in advance

Where do you assign a value to the member variable size? Shouldn't it be set in the constructor?


Jim

thanks...........

but the segmentation fault still persists even after adding.

Quote:

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Originally Posted by sanddune008

thanks...........

but the segmentation fault still persists even after adding.

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1. you need to set 'size' in both constructors

2. since you don't have an assignment operator defined, you get a compiler defined assignment, so when you assign b = a the original pointer that b had is overwritten with the pointer from a. then at the end of your program when the desttructors are called, that pointer is released twice which can cause a fault. plus your original pointer from 'b' is lost and never deallocated.

you need to define an assignment operator that handles the transfer of pointers properly.

SourceForge.net: Raw pointer issues - cpwiki