析构和构造 

#include <iostream>
#include <cstring>
using namespace std;
class Person
{
public:
    Person()
    {
        cout << "构造函数调用" << endl;
        pName = (char *)malloc(sizeof("John"));
        strcpy(pName, "John");
        mTall = 150;
        mMoney = 100;
    }
    ~Person()
    {
        cout << "析构函数调用!" << endl;
        if (pName!=NULL)
        {
            free(pName);
            pName = NULL;
        }
    }
public:
    char *pName;
    int mTall;
    int mMoney;
};
int main()
{
    Person person;
    cout << person.pName << endl;
    cout << person.mTall << endl;
    cout << person.mMoney << endl;
    return 0;
}
 1 #include <iostream>
 2 #include <cstring>
 3 using namespace std;
 4 class Person
 5 {
 6 public:
 7     Person()
 8     {
 9         cout << "无参构造" << endl;
10     }
11     Person(int age)
12     {
13         cout << "有参构造" << endl;
14         mAge = age;
15     }
16     //拷贝构造
17     Person(const Person &person)
18     {
19         cout << "拷贝构造" << endl;
20         mAge = person.mAge;
21     }
22     void PrintPerson()
23     {
24         cout << "Age:" << mAge << endl;
25     }
26 private:
27     int mAge;
28 };
29 //无参调用
30 void test01()
31 {
32     Person person1;
33     person1.PrintPerson();
34 }
35 //有参调用
36 void test02()
37 {
38     //第一种括号法
39     Person person01(100);
40     person01.PrintPerson();
41     //调用拷贝构造函数
42     Person person02(person01);
43     person02.PrintPerson();
44     //第二种匿名对象//显式调用
45     Person(200).PrintPerson();
46 
47     Person person03 = Person(300);
48     person03.PrintPerson();
49     //第三种=号法,隐式转换
50     Person person04 = 100;//Person person04=Person(100);
51     person04.PrintPerson();
52 }
53 int main()
54 {
55     test02();
56     return 0;
57 }

 

posted @ 2021-03-13 18:12  丁帅帅dss  阅读(64)  评论(0)    收藏  举报