class

Python - When to create a Class and when to create a Function

由 自作多情 提交于 2020-12-29 13:09:16
问题 Right, so I'm trying to create a Contacts application using Python OOP. I'm fairly new to OOP and still trying to get my head around the concepts. I understand that a Class is a blueprint for all objects. I like to think of a Class as an entity and each Object is a record of that entity. I am from a Database background so that's why I interpret it like this, feel free to correct me. Anyways, in the Contacts app I'm making I've created the Class Contacts as outlined below: class Contacts():

在windows下配置pthread

由 爷，独闯天下 提交于 2020-12-29 07:28:55
Pthread是由POSIX提出的一套通用的线程库，在linux平台下，他被广泛的支持，而windows平台下，却并不被支持，而pthreads-w32为我们提供了解决方案，本文我们准备在我们的windows平台下进行pthread-w32的安装，在网络上有类似的文章，但是讲的都是比较老的平台，在windows8下支持并不全面，不过可以作为参考。我们在这里贴出几个网址，供参考使用。 Windows 7 64bit和Visual Studio 2010下安装及使用Pthread-w32 2.8 windows下使用pthread库(转) 如果你的是XP系统或者win7 32位系统，那么，那两篇文章已经足以你完成pthread-w32的安装了。现在，我们开始讲我们的尝试过程。 一、安装平台 windows8 64位系统，Microsoft Visual Studio 2012 二、pthreads-w32 下载地址 我们这里下载最新版本pthreads-w32-2-9-1 ftp://sourceware.org/pub/pthreads-win32/pthreads-w32-2-9-1-release.zip 下载后解压，可以看到共有三个文件夹 我们用到的主要是“Pre-built.2”这个文件夹下的三个文件夹，分别是动态链接库、头文件、静态链接库 三、配置头文件及静态链接库

C++ - How to access private members of a class, from a static function of the same class?

由 时光总嘲笑我的痴心妄想 提交于 2020-12-26 05:01:42
问题 What I have: So I have a class with a private member, and a static function. The function must really be static and I can't change that. What I want: I need to access, from the static function, the private member. Any ideas? :) Please check the code bellow: class Base { private: int m_member; public: Base() : m_member(0) {}; ~Base() {}; static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode); /* This must really be static because it is coming from C */ };

Servlet监听器

由 落花浮王杯 提交于 2020-12-19 09:45:29
一、监听三个域对象创建和销毁的事件监听器 1. ServletContextListener接口 创建类MyServletContextListener实现ServletContextListener public class MyServletContextListener implements ServletContextListener { public void contextDestroyed(ServletContextEvent arg0) { System.out.println(arg0.getServletContext() + "被创建了"); } public void contextInitialized(ServletContextEvent arg0) { System.out.println(arg0.getServletContext() + "被销毁了"); } } 在web.xml文件中配置 <listener> <listener-class>cn.class3g.web.listener.MyServletContextListener </listener-class> </listener> 执行结果为：启动服务器时打印”被创建了“停止服务器时打印“被销毁了”； 2.HttpSessionListener接口

Promise override causes then calls to error

由 折月煮酒 提交于 2020-12-13 07:56:18
问题 I have the following sample code. class test extends Promise { constructor(executor) { super(executor) } static getPromise() { return new test((res, rej) => { res(true) }) } } let t = test.getPromise() t.then(value => {console.log("Works")}, value => {console.log("Works")}) this works just fine, but if I were to put the same function directly into the super function, it throws an error. class test extends Promise { constructor(executor) { super((res, rej) => { res(true) }) } static getPromise

Java Class and Interface Name Collision

由 蹲街弑〆低调 提交于 2020-12-13 04:16:49
问题 interface A { void print(); } class A implements A { public void print() { System.out.println("Hello"); } public static void main(String args[]) { A a=new A(); a.print(); } } When i am using this code then it is saying "duplicate class:A". Why so? Can I not have same class and interface name 回答1: You can't have a class and an interface with the same name because the Java language doesn't allow it. First of all, it's ambiguous. If you declare a variable like this: A a; What is the type of that

Java Class and Interface Name Collision

由 青春壹個敷衍的年華 提交于 2020-12-13 04:12:26
问题 interface A { void print(); } class A implements A { public void print() { System.out.println("Hello"); } public static void main(String args[]) { A a=new A(); a.print(); } } When i am using this code then it is saying "duplicate class:A". Why so? Can I not have same class and interface name 回答1: You can't have a class and an interface with the same name because the Java language doesn't allow it. First of all, it's ambiguous. If you declare a variable like this: A a; What is the type of that

What does the `#` symbol do in JavaScript?

由 喜欢而已 提交于 2020-12-13 03:14:58
问题 I encountered code that contained the # sign. What is it used for? The code looks something like this: class someObject{ #someMethod(){ //do something } } 回答1: It's a sigil (rather than an operator) that indicates that the member is private — in this case, a private method, but it's also used for private fields. You can't use a private method or private field in code outside the class declaring them. For instance: class Example { doSomething() { this.#method("from doSomething"); // <== Works

What does the `#` symbol do in JavaScript?

由 女生的网名这么多〃 提交于 2020-12-13 03:14:34
问题 I encountered code that contained the # sign. What is it used for? The code looks something like this: class someObject{ #someMethod(){ //do something } } 回答1: It's a sigil (rather than an operator) that indicates that the member is private — in this case, a private method, but it's also used for private fields. You can't use a private method or private field in code outside the class declaring them. For instance: class Example { doSomething() { this.#method("from doSomething"); // <== Works

What does the `#` symbol do in JavaScript?

由 女生的网名这么多〃 提交于 2020-12-13 03:13:16
问题 I encountered code that contained the # sign. What is it used for? The code looks something like this: class someObject{ #someMethod(){ //do something } } 回答1: It's a sigil (rather than an operator) that indicates that the member is private — in this case, a private method, but it's also used for private fields. You can't use a private method or private field in code outside the class declaring them. For instance: class Example { doSomething() { this.#method("from doSomething"); // <== Works
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