错误:预期的不合格ID

Question

所以,我一直在寻找答案,多个人都有相同的错误响应,但我无法看到他们的错误如何修复我的代码.

我昨天开始尝试使用c ++,但我很熟悉Python,但也有C#

我正在制作一本简单的联系簿,仅供学习.我没有完成这个类或任何其他实现,只需先修复它.

确切的错误是

kontaktbok.cpp:9: error: expected unqualified-id before 'public'

代码在这里

#include <iostream>
#include <string>
#include <sstream>

using namespace std;

bool running = true;

public class Contact
{
    private:
        string firstname   = "";
        string lastname    = "";
        string phonenumber = "";

    public:
        Contact()
        {
            this.firstname = "Alfred";
        }
};

int main()
{
        cout << "Welcome to the Contact book!" << endl <<
                "Made by X";
    while (running)
    {
        cout << "1. Add contact"    << endl
             << "2. List contacts"  << endl
             << "3. Quit"           << endl;
        cout << "Choice: ";
        string mystr;
        getline(cin, mystr);
        int choice;
        stringstream(mystr) >> choice;
        switch (choice)
        {
            case 1: cout << "asd";
            case 2: cout << "asd2";
            case 3: running = false;
            default : cout << "Invalid integer";
        }
    }
    return 0;
}

提前致谢!

Answer 1

public class Contact是无效的C++,请class Contact改用.

Answer 2

这些更改将解决您的问题,public Class是无效的C++,应该只是class:

class Contact
{
  private:
      string firstname ;
      string lastname  ;
      string phonenumber ;

  public:
    Contact()
    {
        this->firstname = "Alfred";
    }

  };

此外,您应该->在解除引用时使用this它不是普通的指针struct或class使用.有效的指针.另外,成员变量应该在构造函数中初始化,如果你想要空,则string默认构造函数构造一个空字符串.