The difference between delete and delete[] in C + +

Reprint http://www.cnblogs.com/charley_yang/archive/2010/12/08/1899982.html

C + + tells us to use delete[] when reclaiming the memory space of a single object allocated with new and using Delete to reclaim the memory space of a set of objects allocated with new[].
About new[] and delete[], which are divided into two situations: (1) Allocate and reclaim space for basic data types, and (2) allocate and reclaim space for custom types.

Please see the procedure below.

#include <iostream>;using namespacestd;classT { Public: T () {cout<<"Constructor"<<Endl;} ~t () {cout <<"destructor"<<Endl;}}; intMain () {Const intNUM =3; T* P1 =NewT[num]; cout<< Hex << p1 <<Endl; //delete[] P1;  DeleteP1; T* P2 =NewT[num]; cout<< P2 <<Endl; Delete[] p2;}

You can run this program on your own, and look at the different results of the delete P1 and delete[] P1, and I won't post the results here.

From the running results we can see that delete P1 in the process of reclaiming space, only p1[0] This object called the destructor, other objects such as p1[1], p1[2] and so on have not called their own destructor, this is the crux of the problem. If you use delete[], all objects will first call their own destructors before reclaiming the space.

Basic types of objects do not have destructors, so it should be possible to reclaim the array space of basic types with delete and delete[], but only with delete[] for an array of class objects. For a single object of new, you can only use Delete to reclaim space with delete[].

　　So a simple use principle is: New and delete, new[] and delete[] corresponding to use.

The difference between delete and delete[] in C + +