8 月 18 日 笔记

#include "stdafx.h"
#include <iostream>
class Screen{
public:
	using pos = std::string::size_type;
	Screen() = default;
	Screen(pos ht, pos wd, char c) :height(ht), width(wd),
	contents(ht * wd, c)  { }
	char get() const
	{
		return contents[cursor];
	}
	inline char get(pos ht, pos wd) const;
	Screen &move(pos r, pos c);
private:
	pos cursor = 0;
	pos height = 0 , width = 0;
	std::string contents;
};

using namespace std;
int  main()
{

	
	system("pause");
    return 0;
}

// C++primer.cpp : 定义控制台应用程序的入口点。
//
#include "stdafx.h"
#include <iostream>
class Screen{
public:
	using pos = std::string::size_type;
	Screen() = default;
	Screen(pos ht, pos wd, char c) :height(ht), width(wd),
	contents(ht * wd, c)  { }
	char get() const
	{
		return contents[cursor];
	}
	inline char get(pos ht, pos wd) const;
	Screen &move(pos r, pos c);
public:
	Screen &set(char);
	Screen &set(pos, pos, char);

private:
	
	pos cursor = 0;
	pos height = 0 , width = 0;
	std::string contents;
};

inline Screen &Screen::set(char c)
{
	contents[cursor] = c;
	return *this;
}
inline Screen &Screen::set(pos r, pos col, char ch)
{
	contents[r*width + col] = ch;
	return *this;
}
using namespace std;
int  main()
{
	Screen myScreen(5, 5, 'X');
	myScreen.move(4, 0).set('#');
	cout << endl;
	
	system("pause");
    return 0;
}

#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
class Screen {
	unsigned height = 0, width = 0;
	unsigned cursor = 0;
	string contents;
public:
	Screen() = default;
	Screen(unsigned ht, unsigned wd) :height(ht), width(wd), contents(ht*wd, ' ') {}
	Screen(unsigned ht, unsigned wd, char c) :height(ht), width(wd), contents(ht*wd, c) {}

	Screen& move(unsigned r, unsigned c)
	{
		cursor = r*width + c;
		return *this;
	}
	Screen& set(char ch)
	{
		contents[cursor] = ch;
		return *this;
	}
	Screen& set(unsigned r, unsigned c, char ch)
	{
		contents[r*width + c] = ch;
		return *this;
	}
	Screen& display()
	{
		cout << contents;
		return *this;
	}
};
int  main()
{
	Screen myScreen(5, 5, 'X');
	myScreen.move(4, 0).set('#').display();
	cout << endl;
	myScreen.display(); //如果取消&符号，上一排输出的是副本，然后这就是新的就没有#
	system("pause");
    return 0;
}
​