网易云课堂_C++程序设计入门(上)_第4单元：物以类聚 – 对象和类_第4单元作业【2】- 在线编程（难度：中）

#include <iostream>

class Screen
{
public:
	int getWidth();
	int getHeight();
	int setWidth(int width);    //return width
	int setHeight(int height);  //return height
public:
	Screen(int width, int height);//有参构造函数
	Screen();//默认构造函数
private:
	int width;//屏幕的宽
	int height;//屏幕的高
private:
	void exitWhenInvalidScreen(int width, int height);//检测屏幕的宽与高是否 符合逻辑
};

int Screen::getWidth()
{
	return width;
}

int Screen::getHeight()
{
	return height;
}

int Screen::setWidth(int width)    //return width
{
	this->width = width;
	return width;
}

int Screen::setHeight(int height)  //return height
{
	this->height = height;
	return height;
}

Screen::Screen(int width, int height)//有参构造函数
{
	exitWhenInvalidScreen(width, height);//检测屏幕的宽与高是否 符合逻辑
	std::cout << "screen" << std::endl;
	this->width = width;
	this->height = height;
}

Screen::Screen()//默认构造函数
{
	std::cout << "screen" << std::endl;
	this->width = 640;
	this->height = 480;
}

void Screen::exitWhenInvalidScreen(int width, int height)//检测屏幕的宽与高是否 符合逻辑
{
	if (width <= 0 || height <= 0)//宽度和高度必须大于0像素（不能等于0像素）
	{
		std::cout << "invalid screen size";//如果宽或者高不满足上述任一条件，则整个程序仅仅输出字符串"invalid screen size"，然后退出程序
		exit(0);
	}

	if (width > 1000 || height > 1000)//宽度和高度均不得大于1000像素(可以等于1000像素)
	{
		std::cout << "invalid screen size";
		exit(0);
	}
}

int main() {
	int width, height;
	std::cin >> width >> height;
	Screen screen1(width, height);
	Screen screen2;

	screen2.setWidth(800);
	screen2.setHeight(600);

	std::cout << screen1.getWidth() << ‘ ‘ << screen1.getHeight() << std::endl;
	std::cout << screen2.getWidth() << ‘ ‘ << screen2.getHeight();

#ifdef DEBUG
	std::cin.get();
#endif
	return 0;
}