class Student { public: Student(double i, string n) { name = n; id = i; total++; } virtual ~Student() {} static int getTotal() { return total; } private: static int total; string name; double id; }; class MaleStudent : private Student { public: MaleStudent(double i, string n) { name = n; id = i; maleCount++; } ~MaleStudent() {} static int getMaleCount() { return maleCount; } private: static int maleCount; string name; double id; }; class FemaleStudent : private Student { public: FemaleStudent(double i, string n) { name = n; id = i; femaleCount++; } ~FemaleStudent() {} static int getFemaleCount() { return femaleCount; } private: static int femaleCount; string name; double id; }; int Student::total = 0; int MaleStudent::maleCount = 0; int FemaleStudent::femaleCount = 0; int main() { MaleStudent male1(1234,"张三"); FemaleStudent female1(1111,"李四"); std::cout << "Male students: " << MaleStudent::getMaleCount() << std::endl; std::cout << "Female students: " << FemaleStudent::getFemaleCount() << std::endl; std::cout << "Total students: " << Student::getTotal() << std::endl; return 0; }修改代码“Student”: 没有合适的默认构造函数可用

好的，对于这份代码，我们需要添加一个默认构造函数来解决“Student: 没有合适的默认构造函数可用”的问题。默认构造函数是一个没有参数的构造函数，它在对象被创建时会被调用。

在这份代码中，我们可以在 `Student` 类中添加一个默认构造函数，比如这样：

class Student {
public:
    Student() : name(""), id(0.0) {
        total++;
    }

    Student(double i, string n) : name(n), id(i) {
        total++;
    }

    virtual ~Student() {}

    static int getTotal() {
        return total;
    }

private:
    static int total;
    string name;
    double id;
};

int Student::total = 0;

这里我们实现了一个没有参数的构造函数，它会将 `name` 初始化为空字符串，将 `id` 初始化为 0.0，并且将 `total` 自增。然后我们在 `main()` 函数中创建 `MaleStudent` 和 `FemaleStudent` 对象时就不会再出现“没有合适的默认构造函数可用”的错误了。

相关问题

检查错误： class Student { public: static int TotalNumber; void show3() { cout << "总人数：" << TotalNumber << endl; } }; int Student::TotalNumber = 0; class ManStudent:private Student { private: int number; public: ManStudent(int n) { number = n; } ~ManStudent(); void show() { Student::TotalNumber += number; cout << "男生人数：" << number << endl; } }; class WomanStudent:private Student { private: int number; public: WomanStudent(int n) { number = n; } ~WomanStudent(); void show() { Student::TotalNumber += number; cout << "女生人数：" << number << endl; } }; int main() { ManStudent s1(139); WomanStudent s2(136); Student s3; s1.show(); s2.show(); s3.show(); return 0; }

该代码存在两处错误：

1. 析构函数未定义

在ManStudent和WomanStudent类中，都声明了析构函数，但是没有定义，应该在类外部定义析构函数。

2. show3函数未被调用

在main函数中，虽然定义了一个Student对象s3，但是没有调用其show3函数，因此总人数无法输出。可以在main函数中加上s3.show3()语句，输出总人数。

修改后的代码如下：

#include <iostream>
using namespace std;

class Student {
public:
    static int TotalNumber;
    void show3()
    {
        cout << "总人数：" << TotalNumber << endl;
    }
};

int Student::TotalNumber = 0;

class ManStudent : private Student {
private:
    int number;
public:
    ManStudent(int n)
    {
        number = n;
    }
    ~ManStudent() {}
    void show()
    {
        Student::TotalNumber += number;
        cout << "男生人数：" << number << endl;
    }
};

class WomanStudent : private Student {
private:
    int number;
public:
    WomanStudent(int n)
    {
        number = n;
    }
    ~WomanStudent() {}
    void show()
    {
        Student::TotalNumber += number;
        cout << "女生人数：" << number << endl;
    }
};

int main()
{
    ManStudent s1(139);
    WomanStudent s2(136);
    Student s3;
    s1.show();
    s2.show();
    s3.show3();
    return 0;
}

#include <iostream> #include <string> using namespace std; class Person{ private : string name; public: Person(string n):name(n){} string getName() const{ return name; } }; class Student : public Person { private: string className; public: Student(string n, string c): Person(n) , className(c){} string getClassName()const { return className; } }; class Worker : public Person { private: string job; public: Worker(string n, string j): Person(n) , job(j){} string getJob() const { return job; } }; class StudentWorker : public Student ,public Worker { private: double salary; public: StudentWorker(string n, string c, string j,double s):Student (n,c),Worker(n,j),salary(s){} void show() const{ cout <<"姓名"<<getName()<<endl; cout <<"班级"<<getClassName()<<endl; cout <<"职业"<<getJob()<<endl; cout <<"工资"<<salary<<endl; } }; int main(){ StudentWorker sw("小宇","一班","教师","6000"); sw.show(); return 0; }运行中哪儿有错误

代码中的错误在于在定义 `StudentWorker` 类时，使用了多重继承，同时继承了 `Student` 和 `Worker` 类。而 `Student` 和 `Worker` 类都继承了 `Person` 类，因此在 `StudentWorker` 类中会有两个 `Person` 对象。这将导致 `getName()` 函数调用不明确，编译器会发生二义性错误。

要解决这个问题，可以使用虚继承。在 `Student` 和 `Worker` 类中将 `Person` 继承声明为 `virtual` 即可：

class Student : virtual public Person { ... };
class Worker : virtual public Person { ... };

这样在 `StudentWorker` 类中就只有一个 `Person` 对象了。修改后的代码如下：

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

class Person{ 
private: 
    string name; 
public: 
    Person(string n):name(n){} 
    string getName() const{ 
        return name; 
    } 
}; 

class Student : virtual public Person { 
private: 
    string className; 
public: 
    Student(string n, string c): Person(n) , className(c){} 
    string getClassName()const { 
        return className; 
    } 
}; 

class Worker : virtual public Person { 
private: 
    string job; 
public: 
    Worker(string n, string j): Person(n) , job(j){} 
    string getJob() const { 
        return job; 
    } 
}; 

class StudentWorker : public Student ,public Worker { 
private: 
    double salary; 
public: 
    StudentWorker(string n, string c, string j,double s):Student (n,c),Worker(n,j),salary(s){} 
    void show() const{ 
        cout <<"姓名"<<getName()<<endl; 
        cout <<"班级"<<getClassName()<<endl; 
        cout <<"职业"<<getJob()<<endl; 
        cout <<"工资"<<salary<<endl; 
    } 
}; 

int main(){ 
    StudentWorker sw("小宇","一班","教师",6000); 
    sw.show(); 
    return 0; 
}

注意，还有一个错误是 `StudentWorker` 类的最后一个参数传入了一个字符串 `"6000"`，而 `salary` 的类型是 `double`，应该传入一个数值类型的参数，例如 `6000.0`。修改后的代码已经修正了这个错误。