5/28 C++: class Sqaure

#include <iostream>
using namespace std;

/* Square.h */

class Square{
    private:
        // 資料(變數部分)
        int len;

    public:
        // 方法;功能(函式部分)
        Square(){
            len = 0;
        }

        Square(int a){
            len = a;
        }

        void setLen(int a){
            len = a;
        }

        int getLen(){
            return len;
        }

        int area(){
            return len * len;
        }
};

/* Square.h */

int main(){
    Square s1(10);
    Square s2;
    s2.setLen(20);

    cout << s1.area() << endl;
    cout << s2.area() << endl;


    return 0;
}