在堆上创建的变量,指向同一变量的2个指针有不同的地址？

Question

我刚刚学会了堆栈和堆之间的区别.在为我创建一个将在堆上动态分配内存的函数之后,我返回指针并显示(进出函数)每个指针的地址和值.

这些值是我所期望的,但是堆上相同内存块的地址是不同的,这是我没想到的.

为什么？pHeap2和pTemp不应指向同一地址吗？

#include <iostream>
using namespace std;

int* intOnHeap(); // returns an int on the heap
int main()
{
 int* pHeap = new int; // new operator allocates memory on the heap and returns its address
       // 'new int' allocates enough memory on heap for one int and returns the address on the heap for that chunk of memory
       // 'int* pHeap' is a local pointer which points to the newly allocated chunk of memory
 *pHeap = 10;
 cout << "*pHeap: " << *pHeap << "\n\n";

 int* pHeap2 = intOnHeap();
 cout << "pHeap2:\n-----------" << endl;
 cout << "Address:\t" << &pHeap2 << "\n";
 cout << "Value:\t\t" << *pHeap2 << "\n\n";

 cout << "Freeing memory pointed to by pHeap.\n\n";
 delete pHeap;

 cout << "Freeing memory pointed to by pHeap2.\n\n";
 delete pHeap2;

// get rid of dangling pointers
    pHeap = 0;
    pHeap2 = 0;

 system("pause");
 return 0;
}

int* intOnHeap()
{
 int* pTemp = new int(20);
 cout << "pTemp:\n-----------" << endl;
 cout << "Address:\t" << &pTemp << "\n";
 cout << "Value:\t\t" << *pTemp << "\n\n";
 return pTemp;
}

输出:

*pHeap: 10

pTemp:
-----------
Address:        0042FBB0
Value:          20

pHeap2:
-----------
Address:        0042FCB4
Value:          20

Freeing memory pointed to by pHeap.

Freeing memory pointed to by pHeap2.

Press any key to continue . . .

Answer 1

您正在报告指针的地址,而不是指针指向的地址.当然,指针的地址对于pTemp和不同pHeap2; 这些是恰好指向内存中相同地址的不同指针.删除&前缀pTemp并pHeap2查看您期望的结果.

图片是这样的:

0042FBB0           0042FBC0     0042FCB4
------------       ------       ------------
| 0042FBC0 |------>| 20 |<------| 0042FBC0 |
------------       ------       ------------
pTemp                           pHeap2

在这里,你有一个&pTemp是0042FBB0和&pHeap2是0042FCB4.我为地址指定了一个地址pTemp并pHeap2指向(当然,结果可能因运行而异),如果你删除了&前缀pTemp,pHeap2那么你会看到0042FBC0在每种情况下打印.