问题描述

请问大家一个c++primer练习7.27的问题，按照习题答案这样写，提示我参数过多

#include <iostream>
#include <string>
#include<vector>
using namespace std;

class Screen
{
private:
    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){}
public:
    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);
        cout << endl;
        myScreen.display(cout);
        cout << endl;

    }

};

解决方案

int main()
{
Screen myScreen(5, 5, 'X');
myScreen.move(4, 0).set('#').display(cout);
cout << endl;
myScreen.display(cout);
cout << endl;

}

这个应该写在类外面

myScreen.display(cout);
这个去掉括号里的cout

解决方案二：

#include
#include
#include
using namespace std;

class Screen
{
private:
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){}
public:
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();
cout << endl;
return 1；
}

解决方案三：

main函数在调用display函数是为什么有实参，而你的display的定义中没有参数。

解决方案四：

首先，你的主函数应该放在类外。
其次，主函数中的display不应该有参数，因为你声明时就没有参数

解决方案五：

谢谢大家的帮助，有你们太好了，刚开始学习c++类没多久，

解决方案六：

myScreen.move(4, 0).set('#').display(cout);

.display(cout);

不应该有参数的