c++中类的初次接触

下面是我写的简单的代码，初次接触c++中的类，c++真的是博大精深啊，学习c++的路还很长，加油！

 /*q1.cpp*/
 //一个简单的类极其实例化
 #include<iostream>
 using namespace std;

 class Point{
     public:
         //设置坐标
         void setPoint(int x,int y){
             xPos = x;
             yPos = y;
         }
         //打印坐标
         void printPoint(){
             cout<<"x = "<<xPos<<endl;
             cout<<"y = "<<yPos<<endl;
         }
         //在类外定义函数
         void foo();
     private:
         int xPos;
         int yPos;
 };
 //类外定义的函数
 void Point::foo(){
     cout<<"foo是类外定义的函数"<<endl;
 }

 int main(){
     Point point;
     point.setPoint(,);
     point.printPoint();
     point.foo();
     return ;
 }

 /*q2.cpp*/
 //检测一下public,private,protect的使用权限
 #include<iostream>
 using namespace std;
 class Animal{
     public:
         string a = "a dog";
         void show1(){
             cout<<a<<endl;
         }
     protected:
         string b = "a snake";
         void show2(){
             cout<<b<<endl;
         }
     private:
         string c = "a turtle";
         void show3(){
             cout<<c<<endl;
         }

 };
 //只有在类中的public中定义的属性和方法才能从类的外部访问
 int main(){
     Animal dog;
     cout<<dog.a<<endl;
     dog.show1();
     return ;
 }