#include<iostream>
#include<string>
using namespace std;
class People
{
public:
People(string, string ,int); // 宣告一下
void display()
{
cout<<"姓名:"<<name<<endl;
cout<<"性别:"<<sex<<endl;
cout<<"年龄:"<<age<<endl;
}

private:
string name;
string sex;
int age;
};

People::People(string n,string s,int a)
{
name=n;
sex=s;
age=a;
}

int main()
{
People p1("张宏宇","男",21);
p1.display();
return 0;
}



为什么编译不能通过呢？错误指向People::People(string n,string s,int a)这一行

#include<iostream>
#include<string>
using namespace std;
class People
{
public:
void display()
{
cout<<"姓名:"<<name<<endl;
cout<<"性别:"<<sex<<endl;
cout<<"年龄:"<<age<<endl;
}

//如果你没有在你所定义的类中申明一个构造函数的话，系统会字行产生一个默认的构造函数
你自然是不能自己在类外定义一个构造函数了

private:
string name;
string sex;
int age;
};

People::People(string n,string s,int a)
{
name=n;
sex=s;
age=a;
}

int main()
{
People p1("张宏宇","男",21);
p1.display();
return 0;
}



为什么编译不能通过呢？错误指向People::People(string n,string s,int a)这一行