Difference between delete and delete[]?

[Hopplos]

In regard to the following FAQ...

This answers the question WHEN to use the different delete operators, not the difference between them.
Does anyone have a more in-depth answer to the original question?


[Andreas]: Added link to the FAQ...

[Paul McKenzie]

Originally posted by Hopplos
In regard to the following FAQ...

This answers the question WHEN to use the different delete operators, not the difference between them.
Does anyone have a more in-depth answer to the original question?


[Andreas]: Added link to the FAQ...

The difference is simple -- the compiler's implementation of operator delete and operator delete[] may be different, and not calling the correct one may introduce undefined behavior or memory leaks.

Also operator delete and operator delete[] can be overloaded. The programmer who has overloaded these operators may have written totally different implementations of delete and delete[]. The programmer who calls the wrong version, again, may introduce bugs by using the wrong form of delete.

For example, consider the following code:

class A
{
};

class foo
{
    public:
         A *p;
         foo() { p = new A; }
         ~foo (delete p;}
};

int main()
{
    foo *pFoo = new foo[50];
    delete pFoo; // incorrect
}

For most implementations, the incorrect call "delete pFoo" will only delete foo[0]. The other foo's are left undestroyed since you didn't indicate that an array of foo's are to be destroyed.

Regards,

Paul McKenzie