C++ 错误：预期的不合格 ID
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error: expected unqualified-id
提问by Johan Bj?reholt
So, i have searched around for answers, and multiple people have got the same error response but i cannot see how their errors could fix my code.
所以，我四处寻找答案，很多人都得到了相同的错误响应，但我看不出他们的错误如何修复我的代码。
I started trying out c++ yesterday, but i am experienced with mostly Python but also C#
我昨天开始尝试 C++，但我对 Python 和 C# 都有经验
I am making a simple contact book, just for learning. I am not done with the class or any other implementation, just need this fixed first.
我正在制作一本简单的通讯录，仅供学习。我没有完成类或任何其他实现，只需要先修复这个。
the exact error is
确切的错误是
kontaktbok.cpp:9: error: expected unqualified-id before 'public'
And the code is here
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;
}
Thanks in advance!
提前致谢！
回答by Luchian Grigore
public class Contactis not valid C++, use class Contactinstead.
public class Contact不是有效的 C++，请class Contact改用。
回答by Shafik Yaghmour
These changes will fix your issue, public Classis not valid C++, it should be just class:
这些更改将解决您的问题，public Class不是有效的 C++，它应该只是class：
class Contact
{
private:
string firstname ;
string lastname ;
string phonenumber ;
public:
Contact()
{
this->firstname = "Alfred";
}
};
Also, you should be using ->when dereferencing thisit is a pointer not a plain structor classin which using .would be valid. Also, member variables should be initialized in the constructor, if you want empty strings the default constructor constructs a empty string.
此外，->当取消引用this它是一个指针而不是普通指针struct或class使用.将有效时，您应该使用。此外，成员变量应该在构造函数中初始化，如果你想要 empty strings 默认构造函数构造一个空 string。
