小编jw1*_*294的帖子

我有一个返回bool的函数:

bool restart()
{
    std::string answer;
    bool answered = false;
    while(answered == false)
    {
        cout << endl << endl << "Do you want to play again? y/n : ";
        cin >> answer;
        if(answer == "y" || answer == "Y" || answer == "1" || answer == "yes")
        {return true;}
        if(answer == "n" || answer == "N" || answer == "0" || answer == "no")
        {return false;}
    }
}

当我用它来调用它时:

cout << restart();

我得到输出:

Do you want to play again? y/n …

如果我有一个包含setup.py文件的 python 项目，我可以运行pip install --user -e .. 这将安装安装文件中列出的所有要求，并将当前项目添加到我的 pip 列表中：

$ pip show project-name                                                                                
Name: project-name                                                                                    
Version: 1.0.0                                                                             
Summary: None                                                                                                                             
Location: /path-to-project/                    
Requires: matplotlib, numpy, scipy, ...                                                    
Required-by:   

默认情况下，这会添加\path-to-project\到用户 PYTHONPATH 中，还是您必须手动执行此操作，以便您可以import project-name从系统上的任何位置导入代码？

我正在学习c ++中的类和对象,并尝试使用以下代码来测试我是否理解它:

#include <iostream>

using namespace std;

class class1
{
    public:
        void write(int x)
        {
             dataObject.var = x;
        }
};

class class2
{
    public:
        void read()
        {
            std::cout << dataObject.var;
        }
};

class data
{
    public:
        int var;
        data()
        {
            var = 1;
        }
};

int main()
{
    data dataObject;
    class1 object1;
    class2 object2;


    object2.read(data dataObject);
    object1.write(2);
    object2.read(data dataObject);

    return 0;
}

这是两个对象都用于修改和使用第三个成员,但我得到以下错误:

In member function 'void class1::write(int)':
line 10: error: 'dataObject' was not declared in this scope

In member …

我刚刚学习了运算符重载,我想尝试创建一个表示复数的对象.我写了以下内容:

#include <iostream>

using namespace std;

class complexNumber
{
    public:
        double re, im;
        complexNumber(){}
        complexNumber(double a, double b)
        {
            re = a;
            im = b;
        }
        complexNumber operator+ (complexNumber b)
        {
            complexNumber c;
            c.re = re + b.re;
            c.im = im + b.im;
        }
        complexNumber operator- (complexNumber b)
        {
            complexNumber c;
            c.re = re - b.re;
            c.im = im - b.im;
        }
};

int main()
{
    complexNumber a(1,2);
    complexNumber b(4,6);
    complexNumber c;
    complexNumber d;

    c = a + b;
    d …