c++ - 尝试在不使用 vector 的情况下在 C++ 中创建同一类的许多对象

Question

所以我的目标是创建同一类的许多对象，而无需多次复制一个对象。我想我通过创建一个指向某个对象的指针数组找到了一种方法，但是我遇到了段错误。
不幸的是，在我尝试做的这个项目中，除了 <cstring> 之外，我没有使用任何其他库。 (我必须在这里补充一点，类的构造函数有一些参数作为输入)。
想法？
这是代码:

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

int main(void)
{
    int i, floor, classroom; //the floor of the school and the classroom the student is heading to
    char *stname;
    typedef Student *stptr;
    stptr *students = new stptr[15];
    for (i = 0; i < 15; i++)
    {
        cin >> stname;
        cin >> floor;
        cin >> classroom;
        students[i] = new Student(stname, floor, classroom);
    }
}

...以及类(class)的代码:

class Student
{
private:
    char *name;
    int no_floor;
    int no_classroom;
public:
    Student(const char *nam, int no_fl, int no_cla) //constructor
    {
        name = new char[strlen(nam + 1)];
        strcpy(name, nam);
        no_floor = no_fl;
        no_classroom = no_cla;
        cout << "A new student has been created! with name " << name << " heading to floor: " << no_floor << " class: " << no_classroom << endl;
    };

    ~Student() //destructor
    {
        cout << "A Student to be destroyed! with name " << name << " is at floor: " << no_floor << " class: " << no_classroom;
        delete[] name;
    };
};

Answer 1

我建议不要使用这种指针混淆:

Student** students = new Student*[15];

更容易理解 IMO。
您可以使用 C++ 提供的工具来自动处理对象的字符串数组:
std::string 对于字符串；
std::vector 为数组。
对象指针在多态的上下文中可能很有用，但即便如此，最好使用 smart pointers .
如pointed out by marcinj in the comments name声明也需要修复。
还有pointed out by Alan Birtles您正在使用 stname未初始化，这可能是段错误的罪魁祸首。
要修复您的代码，使用您当前使用的工具，您应该执行类似于以下代码的操作，请注意，除了修复之外，rule of three必须尊重:

#include <iostream>
#include <cstring>

class Student {
    char *name;
    int no_floor;
    int no_classroom;
public:
    Student(const char *nam, int no_fl, int no_cla){//constructor  
        name = new char[strlen(nam) + 1];
        strcpy(name, nam);
        no_floor = no_fl;
        no_classroom = no_cla;       
        std::cout << "A new student has been created! with name " << name << " heading to floor: " << no_floor << " class: " << no_classroom << std::endl;
    };
    ~Student(){//destructor    
      std::cout << "A Student to be destroyed! with name " << name << " is at floor: " << no_floor << " class: " << no_classroom;
      delete [] name;
    };    
    Student (const Student& student) { //copy constructor
        this->name = nullptr;
        *this = student;
    } 
    Student& operator = (const Student& student){ //assignment operator
        if(this == &student){
            return *this;
        }
        delete [] this->name;
        this->name = new char[strlen(student.name) + 1];
        strcpy(this->name, student.name);
        this->no_classroom = student.no_classroom;
        this->no_floor = student.no_floor;        
        return *this;
    }
};

int main(){

    int i, floor, classroom;
    char *stname = new char[100];
    typedef Student *stptr;
    stptr *students = new stptr[15];

    for (i = 0; i < 15; i++){

        std::cin >> stname;
        std::cin >> floor;
        std::cin >> classroom;
        students[i] = new Student(stname, floor, classroom);
    }
    delete [] stname;

    for (i = 0; i < 15; i++){
        delete students[i];
    }
    //or for the deletion in inverse order
    //for (i = 2; i >= 0; i--){ 
    //    delete students[i];
    //}
    delete [] students;

}