delete class question

[elimin8tor]

Hi, if I have a class A

class A
{
public:
char *pchar;
};

A *pA;

int main()
{
pA = new A[4];
pA[0].pchar = new char[256];

delete[] A;
return 0;
}

is that good enough?
Or do I have to explicitly delete pchar?

[NigelQ]

You have to explicitly call

delete [] pA[0].pchar

Hope this helps,

- Nigel

[Bob Davis]

This is a place where a destructor would be in order. Your A class would become:

class A
{
public:
A();
~A();
char *pchar;
};

A::~A()
{
if (pchar != NULL) delete pchar;
}


Or, if pchar would be pointing to the beginning of a string (a character array), it would be delete [] pchar. Anyway, you get the idea. When an A object goes out of scope, the destructor (~A) will be called, which in this case will deallocate the memory that pchar points to. Hope this helps.

[elimin8tor]

thx Bob, works perfectly.

[Graham]

One thing to note, though: you can't (or at least shouldn't) mix new with delete[] or new[] with delete. Since you have no way of enforcing one form of new over another (because of the public data member), you lay yourself open to some hard-to-find bugs. It would be much better to make the data member private and use public member functions to do the allocation - that way you control which form of new/delete you use.

Or, even better, use std::string, not char*.