计算机程序设计c++ 10-5：类的实例——Person

Person 类的定义

class Person
{
    
     
	char Name[9];
	char Sex;
	int Age;
	public:
		Person( )  // 构造函数
		{
    
    
			strcpy(Name,"XXX");
			Age = 0;
			Sex = ' ';
		}
		
		~Person( ) // 析构函数
		{
    
    cout<<"Now destroying Person"<<endl; }
		
		void Register(char *name, int age, char sex);
		void ShowMe( );
};

类外定义函数

void Person::Register(char *name, int age, char sex)
{
    
    
	strcpy(Name,name);
	Age = age;
	Sex = sex;
}


void Person::ShowMe()
{
    
     
	cout<<Name<<'\t'<<Age<<'\t'<<Sex<<endl;
}

Person 类函数测试主函数

int main()
{
    
    
	Person person1, person2;
	cout<<"person1:\t";
	person1.ShowMe();
	person1.Register("zhang3",19,'m');
	cout<<"person1:\t";
	person1.ShowMe();
	cout<<"person2:\t";
	person2.ShowMe();
	person2=person1;
	cout<<"person2:\t";
	person2.ShowMe();
	return 0;
}

完善Person类

完善person类的定义

• 增加身份证号码，可以定长char Pid[19];
• 增加住址，住址数据无法定长度，就是字符指针

Person类的数据成员定义如下：

class Person
{
    
    
	private:
		char Name[9];
		char Sex;
		int Age;
		char Pid[19];
		char *Addr;
	public:
		……
}

实现

class Person
{
    
    
	char Name[9];
	char Sex;
	int Age;
	char Pid[19];
	char *Addr;

	public:
		Person()
		{
    
    
			strcpy(Name, "xxxxxxxx");
			Age = 0;
			Sex = 'x';
			strcpy(Pid, "xxxxxxxxxxxxxxxxxx");
			Addr=NULL;
		}

		Person(char *N, int A, char S,char *P,char *Ad)
		{
    
    
			strcpy(Name,N);
			Age = A;
			Sex = S;
			strcpy(Pid,P);
			int L=strlen(Ad);
			Addr=new char[L+1];
			strcpy(Addr,Ad);
		}

		~Person( )
		{
    
    
			cout<<"Now destroying Person"<<Name<<endl;
			delete [ ] Addr;
		}
		
		void Register( char *name, int age, char sex,char *pid,char *addr);
		void ShowMe( );
};

类外定义成员函数

void Person::Register(char *name,int age,char sex,char *pid,char *addr)
{
    
    
	strcpy(Name,name);
	Age = age;
	Sex = sex;
	strcpy(Pid, pid);
	if(Addr!=NULL)
		delete [ ] Addr;
	int L=strlen(addr);
	Addr = new char[L+1];
	strcpy(Addr,addr);
}

void Person::ShowMe()
{
    
    
	cout << Name << " " << Age << " " << Sex << " " << Pid << " ";
	if(Addr != NULL)  // 需要判断是否为空指针
		cout<<Addr;
	cout << endl;
}

测试主函数

int main()
{
    
    
	Person person1;
	Person person2("张三",19,'m',"610103199409192839","中国西安市咸宁西路29号");
	Person person3;
	cout<<"person1: ";
	person1.ShowMe();
	cout<<"person2: ";
	person2.ShowMe();
	person3.Register("李四",29,'w',"610103198409192493","中国上海市华山北路1845号");
	cout<<"person3: ";
	person3.ShowMe();
	person2.Register("赵五",29,'w',"610103198409152127","中国新疆乌鲁木齐市王家沟12号");
	cout<<"person2: ";
	person2.ShowMe();
	return 0;
}

可以看见析构函数作用了，先删除Person3->Person2->Person1