如何对 class 对象使用删除功能？

Question

本程序是一个学生数据库，具有学生和课程的添加和删除功能。我在成功从数据库中删除特定学生时遇到问题。此外，当我尝试使用新的学生 ID 将多个学生添加到数据库中时，它指出该学生已经在数据库中，而他们不应该在数据库中。我附上了对象 class 的代码片段以及学生的添加和删除函数。任何帮助将不胜感激。干杯.

class student {
public:
    int studentid;
    course * head;
    student (int id){ studentid = id; head = nullptr;}
    student () {head = nullptr;}
};

void add_student(student DB[], int &num_students)
{ 
    int ID;
    cout << "Please enter the id of the student you wish to enter " << endl;
    cin >> ID;
    for(int x = 0; x <num_students; x++)
    { 
        if (DB[x].studentid == ID);
    {  
    cout << "the student is already in the Database" << endl; return; } }
    student numberone(ID);
    DB[num_students] = numberone;
    num_students++; 
}

void remove_student(student DB[], int &num_students)
{ 
    int ID;
    cout << "Enter the student id you wish to delete from the Database " << endl;
    cin >> ID;
    // This is where I have the error
    // student * pointer2 = student(ID);
    //   delete pointer2; 
}

Answer 1

您不能使用 'delete' 运算符，除非您使用 'new' 运算符创建对象

student * pointer2 = student(ID); //wrong 
delete pointer2;

第一个选项是

 student pointer2(ID) //no need to use delete operator here

在此选项中，'.'运算符用于访问 class 成员。例子

pointer2.studentId

第二个选项

'delete'运算符用于释放使用'new'运算符

分配的内存

student * pointer2 = new student(ID);
delete pointer2;

此处'->'运算符用于访问class成员。例子

pointer2->studentId

如何对 class 对象使用删除功能？

How to use delete function for a class object?

c++

delete-operator