浅拷贝与深拷贝探究

 1 #pragma once
 2 class Demo
 3 {
 4 private:
 5     int m_icount;
 6     int *pStr;
 7 public:
 8     Demo(int icount);//构造函数
 9     Demo(const Demo &d);//拷贝构造函数(浅拷贝)
10     ~Demo();//析构函数
11     void setValue(int icount);
12     void printValue();
13     void printAddr();
14 };

 1 #include "Demo.h"
 2 #include <iostream>
 3 using namespace std;
 4 
 5 Demo::Demo(int icount)
 6 {
 7     m_icount = icount;
 8     pStr = new int[m_icount];
 9     for (int i = 0; i < m_icount; i++)
10     {
11         pStr[i] = i;
12     }
13     cout << "\nDemo(int value)构造函数被调用！" << endl;
14 }
15 
16 Demo::Demo(const Demo &d)
17 {
18     m_icount = d.m_icount;
19     //浅拷贝
20     /*pStr = d.pStr;//浅拷贝，赋地址
21     cout << "Demo(const Demo &d)浅拷贝构造函数被调用！" << endl;*/
22 
23     //深拷贝
24     pStr = new int[m_icount];
25     for (int i = 0; i < m_icount; i++)
26     {
27         pStr[i] = d.pStr[i];
28     }
29     cout << "\nDemo(const Demo &d)深拷贝构造函数被调用！" << endl;
30 }
31 
32 Demo::~Demo()
33 {
34     delete[]pStr;
35     pStr = NULL;
36     cout << "\n~Demo()析构函数被调用！" << endl;
37 }
38 
39 void Demo::setValue(int icount)
40 {
41     m_icount = icount;
42     cout << "\nsetValue(int icount)函数被调用！" << endl;
43 }
44 
45 void Demo::printValue()
46 {
47     for (int i = 0; i < m_icount; i++)
48     {
49         cout << pStr[i] << "  ";
50     }
51     cout << "\nDemo::printValue()函数被调用！" << endl;
52 }
53 
54 void Demo::printAddr()
55 {
56     cout << pStr << endl;
57 }
58 
59 int main()
60 {
61     Demo d1(6);
62     cout << "\nd1 : ";
63     d1.printValue();
64 
65     d1.setValue(5);
66     cout << "\nd1 : ";
67     d1.printValue();
68 
69     Demo d2(d1);
70     cout << "\nd2 :";
71     d2.printValue();
72 
73     cout << "\nd1 addr : ";
74     d1.printAddr();
75     cout << "\nd2 addr : ";
76     d2.printAddr();
77 
78     system("pause");
79 }