list std::string constructor type
时间: 2023-11-16 11:05:57 浏览: 151
std::string有4种构造函数类型,分别为:
1. 基于char*的构造函数:可以通过传入char*类型的字符串来创建一个std::string对象。
2. 基于std::string的构造函数:可以通过传入std::string对象来创建另一个std::string对象。
3. 基于迭代器的构造函数:可以利用迭代器来构造std::string对象。
4. 基于重复字符的构造函数:可以通过传入两个参数,一个是单个字符,另一个是重复的次数,来创建一个std::string对象。
相关问题
In function "int main()': error:could not convert '{{"LittleDog",8},{"LittleCat",3},{"LittleLion",5}}' from "<brace-enclosed initializer list>' to ‘std::vector<Animal>' vector <Animal> animalList={{"LittleDog",8},{"LittleCat",3},{"LittleLion",5}}; how to fix this c++ code error?
The error message indicates that you are trying to initialize a `std::vector<Animal>` with a brace-enclosed initializer list, but the conversion is not possible.
To fix the error, you can use the `std::initializer_list` constructor of `std::vector` to initialize the vector with the given elements. Here's an example:
```
#include <vector>
#include <string>
struct Animal {
std::string name;
int age;
};
int main() {
std::vector<Animal> animalList = {
{"LittleDog", 8},
{"LittleCat", 3},
{"LittleLion", 5}
};
// ...
}
```
This code will create a vector of `Animal` objects and initialize it with the given elements using the `std::initializer_list` constructor.
写一段C++代码 要求如下 :Person类student类Teacher类 1.派生中构造函数的完善:调用基类构造函数初始化基类成分 2.teacher类增加其一个课程属性 ,表示其所教授的课程.可采用标准模板库list,存放多个课 程名称。 3.定义一个助教类Assitant,同时继承student类和Teacher类,采用虚继承 4.修改主函数,增加代码测试助教类
以下是符合要求的代码:
```
#include <iostream>
#include <string>
#include <list>
using namespace std;
class Person {
protected:
string name;
int age;
public:
Person(string n, int a) : name(n), age(a) {
cout << "Person constructor called" << endl;
}
};
class Student : public Person {
private:
string school;
public:
Student(string n, int a, string s) : Person(n, a), school(s) {
cout << "Student constructor called" << endl;
}
};
class Teacher : public Person {
private:
list<string> courses;
public:
Teacher(string n, int a, list<string> c) : Person(n, a), courses(c) {
cout << "Teacher constructor called" << endl;
}
void displayCourses() {
for (const auto& course : courses) {
cout << course << endl;
}
}
};
class Assistant : public virtual Student, public virtual Teacher {
public:
Assistant(string n, int a, string s, list<string> c) : Person(n, a), Student(n, a, s), Teacher(n, a, c) {
cout << "Assistant constructor called" << endl;
}
};
int main() {
list<string> courses = {"Math", "Science", "History"};
Assistant assistant("John", 25, "ABC School", courses);
assistant.displayCourses();
return 0;
}
```
在这个代码中,我们定义了三个类:Person、Student和Teacher,其中Student和Teacher都继承自Person。在Student和Teacher类中,我们分别加入了一个成员变量school和courses。同时,我们还定义了一个助教类Assistant,它同时继承自Student和Teacher,并采用了虚继承。
在主函数中,我们首先创建了一个存放课程名称的list,然后用这个list初始化了一个Teacher对象。接着,我们创建了一个Assistant对象,它的构造函数除了调用Person的构造函数之外,还调用了Student和Teacher的构造函数。最后,我们调用Assistant的displayCourses函数,输出助教所教授的所有课程名称。
阅读全文