string snap_name = name_[snap_index];解析

这段代码的功能是从一个名为 `name_` 的字符串数组中获取指定索引位置的元素，并将其赋值给一个名为 `snap_name` 的字符串变量。具体来说，`snap_index` 是一个表示索引位置的整数变量，它指定了要获取的数组元素的位置。`name_` 是一个字符串数组，它存储了多个字符串元素，这些元素可以通过索引位置来访问。`string` 是 C++ 中的一种数据类型，它表示一个字符串。因此，`snap_name` 变量将包含 `name_` 数组中位于 `snap_index` 索引位置的字符串元素。

相关问题

std::string engine_name = "";

这是一个定义了一个名为 `engine_name` 的字符串变量，它的初始值是空字符串。在 C++ 中，`std::string` 是一个字符串类，可以用来表示和操作字符串。定义一个字符串变量时，可以省略初始值，此时它的值为默认值，对于 `std::string` 类型的变量来说，其默认值即为空字符串。

改错#include<iostream> #include<string.h> using namespace std; class Teacher{ public: string teacher_name; int teacher_age; string teacher_duty; teacher(string teacher_name,int teacher_age){ this->teacher_name=teacher_name; this->teacher_age=teacher_age; teacher_duty="教学"; } }; class Student{ public: string student_name; int student_id; string student_duty; student(string student_name,int student_id){ this->student_name=student_name; this->student_id=student_id; student_duty="学习"; } }; class Graduate{ public: string graduate_name; int graduate_age; int graduate_id; string graduate_duty; graduate(string graduate_name,int graduate_age,int graduate_id){ this->graduate_name=graduate_name; this->graduate_age=graduate_age; this->graduate_id=graduate_id; graduate_duty="教学和学习"; } }; int main(){ Teacher teacher("Tom", 35); Student student("John", 2021000); Graduate graduate("Mary", 25, 20210002); cout << teacher.teacher_name << " " << teacher.teacher_age<< " " << teacher.teacher_duty<< endl; cout << student.student_name<< " " << student.student_id << " " << student.student_duty<< endl; cout << graduate.graduate_name<< " " << graduate.graduate_age << " " << graduate.graduate_id<< " " << graduate.graduate_duty<< endl; return 0; }

在类的定义中，构造函数的名称应该与类名完全相同，而你的代码中构造函数的名称与类名不一致，需要修改为以下代码：

#include<iostream> 
#include<string.h>  

using namespace std; 

class Teacher{ 
public: 
    string teacher_name; 
    int teacher_age; 
    string teacher_duty; 
    Teacher(string teacher_name,int teacher_age){ 
        this->teacher_name=teacher_name; 
        this->teacher_age=teacher_age; 
        teacher_duty="教学"; 
    } 
}; 

class Student{ 
public: 
    string student_name; 
    int student_id; 
    string student_duty; 
    Student(string student_name,int student_id){ 
        this->student_name=student_name; 
        this->student_id=student_id; 
        student_duty="学习"; 
    } 
}; 

class Graduate{ 
public: 
    string graduate_name; 
    int graduate_age; 
    int graduate_id; 
    string graduate_duty; 
    Graduate(string graduate_name,int graduate_age,int graduate_id){ 
        this->graduate_name=graduate_name; 
        this->graduate_age=graduate_age; 
        this->graduate_id=graduate_id; 
        graduate_duty="教学和学习"; 
    } 
}; 

int main(){ 
    Teacher teacher("Tom", 35); 
    Student student("John", 2021000); 
    Graduate graduate("Mary", 25, 20210002); 

    cout << teacher.teacher_name << " " << teacher.teacher_age<< " " << teacher.teacher_duty<< endl; 
    cout << student.student_name<< " " << student.student_id << " " << student.student_duty<< endl; 
    cout << graduate.graduate_name<< " " << graduate.graduate_age << " " << graduate.graduate_id<< " " << graduate.graduate_duty<< endl; 
    return 0; 
}