构造函数含有含默认值的参数

//构造函数含有含默认值的参数

#include "stdafx.h"
#include<iostream>
using namespace std;
class Box
{
public:
    Box(int w = 10, int h = 10, int len = 10);
    int volume();
private:
    int height;
    int width;
    int length;
};

Box::Box(int w, int h, int len)
{
    height = h;
    width = w;
    length = len;
}

int Box::volume()
{
    return (height*width*length);
}
int main()
{
    Box box1;
    cout << "the volume of box is" << box1.volume() << endl;
    Box box2(15);
    cout << "the volume of box is" << box2.volume() << endl;
    Box box3(15, 30);
    cout << "the volume of box is" << box3.volume() << endl;
    Box box4(15, 30, 20);
    cout << "the volume of box is" << box4.volume() << endl;
    system("pause");
    return 0;
}