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(10,9);
    point.printPoint();
    point.foo();
    return 0;
}



/*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 0;
}