Deleting a pointer twice

[mehak]

when we delete a pointer that was pointing to an object,the memory allocated in the free store is released ,but if i happen to delete the pointer twice which now points to nothing,i.e.,NULL,it may corrupt the heap store and cause a trap.

[Duthomhas]

Er... what?

Yes, deleting a non-NULL pointer twice causes heap corruption.

No, deleting NULL has no ill effect.

http://www.cplusplus.com/reference/new/operator%20delete/