C++帮助拷贝构造函数

Question

我是一个新的C++，我需要帮助我的程序。所以基本上它是一个可以创建角色的程序。我使用了构造函数，复制构造函数和解构器来创建它。现在有一个问题，每次我都会运行它时，它会给我一个错误，如复制 constructor.exe在0x0F424F98（msvcr110d.dll）这个

未处理的异常：0000005：访问冲突读取位置 0xFEEEFEE2

反正这里是我的代码，并希望如果你能来看看它

#include <iostream> 
#include <string> 
using namespace std; 

class Character { 
private: 
    string* name; 
    int* age; 
    char* gender; 
public: 
    //declaring constructor 
    Character(const string pname, const int page, const char pgender) { 
     cout << "Making new character" << endl; 
     name = new string; 
     age = new int; 
     gender = new char; 
     //assingment operator 
     *name = pname; 
     *age = page; 
     *gender = pgender; 
    } 
    //declaring copy constructor 
    Character(const Character& cName, const Character& cAge, const Character cGender) { 
     cout << "Keeping a copy constructor" << endl; 
     name = new string; 
     age = new int; 
     gender = new char; 
     //assingment operator 
     *name = *cName.name; 
     *age = *cAge.age; 
     *gender = *cGender.gender; 
    } 
    ~Character() { 
     cout << "Deleting the character " << endl; 
     delete name; 
     delete age; 
     delete gender; 
    } 
    //get name 
    string getName() { 
     return *name; 
    } 
    //get age 
    int getAge() { 
     return *age; 
    } 
    //get gender 
    char getGender() { 
     return *gender; 
    } 
}; 
void showCharacter(Character display) { 
    cout << "Charater Name: " << display.getName() << endl; //get name 
    cout << "Character Age: " << display.getAge() << endl; //get age 
    cout << "Character Gender: " << display.getGender() << endl; //get gender 
} 

int main() { 
    //local variables 
    string name; 
    int age; 
    char gender; 
    //user interface 
    cout << "Write your charaters name: "; 
    cin >> name; 
    cout << "Write your character's age: "; 
    cin >> age; 
    cout << "Write you character's gender: "; 
    cin >> gender; 
    //calling constructor 
    Character detail(name,age,gender); 
    //Showing result 
    showCharacter(detail); 
    system("pause"); 
    return 0; 
} 

Answer 1

拷贝构造函数是为了使对象的副本。所以，拷贝构造函数原型为您将

Character (const Character& c); 

你需要声明一个具有Character类型的三个不同的参数。完整的构造将是：

Character(const Character& cName){ 
    cout << "Keeping a copy constructor" << endl; 
    name = new string; 
    age = new int; 
    gender = new char; 
    //assingment operator 
    *name = *(cName.name); 
    *age = *(cName.age); 
    *gender = *(cName.gender); 
    } 

Answer 2

吉姆，

什么，你在呼唤“拷贝构造函数”，因为编译器理解它是不是一个真正的拷贝构造函数。

拷贝构造函数的签名必须是：

Character(Character const& copy); 

实现将类似于你定义了你的拷贝构造函数的方式。

Character(const Character& copy){ 
cout << "Keeping a copy constructor" << endl; 
name = new string; 
age = new int; 
gender = new char; 
//assingment operator 
*name = *copy.name; 
*age = *copy.age; 
*gender = *copy.gender; 
} 

通过稍微不同地声明数据，可以使事情变得简单很多。取而代之的

string* name; 
int* age; 
char* gender; 

您可以使用

string name; 
int age; 
char gender; 

如果你这样做，你并不需要一个明确的拷贝构造函数。编译器定义的拷贝构造函数将工作得很好。你也可以让编译器为你定义析构函数。

Answer 3

这里是你的代码的外观使用对象而不是指针时等。

#include <iostream> 
#include <string> 
using namespace std; 

class Character { 
    private: 
    string name; 
    int age; 
    char gender; 
    public: 
    //declaring constructor 
    Character(const string pname, const int page, const char pgender): 
     name(pname), age(page), gender(pgender) { 
     cout << "Making new character" << endl; 
    } 

    // NO need for explicit copy constructor or destructor. 

    //get name 
    string getName() { 
     return name; 
    } 
    //get age 
    int getAge() { 
     return age; 
    } 
    //get gender 
    char getGender() { 
     return gender; 
    } 
}; 
void showCharacter(Character display) { 
    cout << "Charater Name: " << display.getName() << endl; //get name 
    cout << "Character Age: " << display.getAge() << endl; //get age 
    cout << "Character Gender: " << display.getGender() << endl; //get gender 
} 

int main() { 
    //local variables 
    string name; 
    int age; 
    char gender; 
    //user interface 
    cout << "Write your charaters name: "; 
    cin >> name; 
    cout << "Write your character's age: "; 
    cin >> age; 
    cout << "Write you character's gender: "; 
    cin >> gender; 
    //calling constructor 
    Character detail(name,age,gender); 
    //Showing result 
    showCharacter(detail); 
    system("pause"); 
    return 0; 
}