dynamic memory allocation!!! problem

[mog4kor]

Hello ,

As I am using pointers member variables in my code , I had to create a dynamic memory allocation . But when i tried to delete the allocated memory space I, the compiler crashes and I have no idea ..why??

my code :

Class A{
private:
int max_abc;
B* p_xyz; //B is some other class type
C ** p_abc; //C is some other class type
public:
A(int max_xyz =2, int max_abc =2);
A(const A & Copy); //copy constructor
~A();
}

//and my constructor is as below

A::A (int max_abc )
{
p_abc= new C*[max_abc];

p_xyz= new B;
}

//copy constructor - I had to do deep copy
A:: A(const A & copy)
{
max_abc = copy.max_abc;

p_xyz= new B;
p_xyz= copy.p_xyz;

m_abc = new C*[max_abc];
for(int j=0;j<max_abc;j++)
{
m_abc [j] = new C;
m_abc [j] = copy.m_abc[j];
}
}

//destructor definition

~A()
{
delete [] p_xyz;
for(int j=0;j<max_abc;j++)
{
delete m_abc [j];
}
delete [] m_abc ;
}


I seriously dont understand , why my compiler is crashed . Could some one please let me know, if my above definitions are correct\or reason for compiler crash ?? Please help....Thanks in advance!

[cire]

In your copy constructor this:

    p_xyz= new B;
    p_xyz= copy.p_xyz;

is wrong. Assuming an appropriate overload for operator= can be found or generated you probably meant something like this:

    p_xyz= new B;
    *p_xyz= *copy.p_xyz;

You have similar problems with m_abc's elements.

Also, you cannot use delete[] on p_xyz as you didn't use new[] to allocate it.

[mog4kor]

Hello Cire ,

Thanks alot for your reply . I have modified the code as you suggested and it worked :)

I have one more question. Could you please let me know , what is the idea behind the method declaration below?

Class XYZ ::: method_xyz( Class* p_abc = NULL)

why is pointer initialized in the argument?

Thanks in advance!

[cire]

XYZ::method_xyz has a default argument for its only argument so that if it is called without an argument, it will be as if it was called with the default argument.