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  Understand this in JavaScript

In JavaScript, this is always pointing to the owner of a function or a method. Function Let's check out function first. function introduce() {      alert("Hello, I am Laruence\r\n"); } For this function, what does this point to? In JavaScript, a global function's owner is the current page, i.e, the window object. Because its a method of the window object if we define a global function. Now you should know the this will point to the window object in the above function. ...

   JavaScript,this,event,call     2013-04-03 04:10:03

  Browse OpenJDK Java source code in Eclipse

Java 8 was recently released, many developers are now trying to extract the source code of Java 8 to find out how the new added features such as Lambda expressions, default method in interfaces, new Time API are implemented. How do you manage to download and browse the source code? Today we are going to show how to extract OpenJDK Java source code to Eclipse. Since OpenJDK is adopting Mercurial as its distributed version control system, you need to install Mercurial on your computer first before...

   OpenJDK,Java 8,Source code,Eclipse     2014-06-16 00:53:34

  Using public key authentication in SSH

SSH is a popular cryptographic network protocol for secure network service operation. It is frequently used in remote server login. For a system administrator or software developer, SSH is frequently used to access remote servers or development servers or testing servers etc.  To login with SSH, there are different authentication mechanisms : password, public key and interactive etc. If a remote server needs to be accessed frequently, password authentication may be too troublesome as p...

   LINUX,DEBUG,SSH,PUBLIC KEY     2016-09-10 05:55:46

  Can two new objects point to the same memory address in GoLang?

Do you have any idea what the output will be for below GoLang snippet? package main import ( "fmt" ) type obj struct{} func main() { a := &obj{} fmt.Printf("%p\n", a) c := &obj{} fmt.Printf("%p\n", c) fmt.Println(a == c) } Many people would think that a and c are two different object instances which have different memory addresses. Hence a == c will be false. But if you try to run the above program, you would see below output 0x5781c8 0x5781c8 true To get to know the reason wh...

   GO,GOLANG,VARIABLE ESCAPE,ZEROBASE     2019-04-06 01:19:52

  How to password protect a Winzip file

Winzip files are great ways of sharing documents and images of large sizes over the web or through email, since their reduced size makes it possible for them to be sent and received. Also, it is easier to manage one attachment than multiple. But what if the file contains sensitive information you don’t want snoopers to see? Simply add a password protection in Winzip. Adding a password will ensure more security and reliability of the transported files. How to add a Password to your Zip Fil...

   DATA SECURITY,WINZIP     2019-08-29 11:42:41

  What can CSS :has pseudo class be used for?

CSS's :has is a pseudo-class representing an element if any of the selectors passed as parameters matching at least one element. From the name, it's also easy to understand how it matches elements. The syntax is pretty easy as well: :has([some-selector]) With this pseudo class, it can do lots of things which previously would be challenging or need tweaking the DOM elements with JavaScript. This post will demonstrate what :has can be used for. Introduction Below are a few simple ex...

   CSS,:HAS,:NOT,PSEUDO CLASS     2022-09-18 01:40:54

  Using JavaScript to operate clipboard

Browsers allow JavaScript to read and write data on clipboard. Generally script should not modify user's clipboard to avoid impacting user expectation, but there are cases where this can indeed bring convenience to users. For example, for some code snippet, user can copy it to clipboard with one click instead of select and copy manually. There are three options for clipboard operation provided in JavaScript/browser: document.execCommand() Asynchronous Clipboard API copy and paste events This p...

   JAVASCRIPT,CLIPBOARD,NAVIGATOR.CLIPBOARD     2021-01-23 23:23:34

  My favorite quotes from "The design and evolution of C++"

"The design and evolution of C++" is a book written by the inventor of C++  Bjarne stroustrup. In this book, Bjarne stroustrup presents the definitive insider's guide to the design and development of the C++ programming language. Without ommitting critical details or getting bogged down in technicalities, Stroustrup presents his unique insights into the decisions that shaped C++. In this book, some statements are very impressive. They are concise but convey much information. Here I summariz...

   C++,statements,type system,compatibility     2012-07-16 10:58:10

  Check out YouTube new design

Recently, YouTube has developed its new design, but is is still not officially released. But you can check out the new design now by following the steps below:1. Open http://www.youtube.com on your Chrome or Firefoc2. Press Ctrl + Shift and J in Chrome to open the Developer Tools and Press Ctrl+Shift and K in    Firefox3. On the bottom part of the development tool, you can type some commands there. Copy the following code and paste on the console window on the bottomdocument.cooki...

   YouTube,New design,Chrome,Firefox,How to     2011-11-20 11:38:58

  Problem and Solution for Installing wxPython on Ubuntu 20.04

When we try to install wxPython lib on Ubuntu system to do software GUI development, most of time we may meet some installation and lib dependency problems. For the latest Ubuntu version, the problems still happen. Below are some common problems which happened frequently and their solution: --------------------------------------------------------------------------------------------------------------- Problem [1]: Install wxPython on Ubuntu 20.04 fail because of dependency package Gtk is not in...

   PYTHON,WXPYTHON,UBUNTU 20.04     2020-09-09 05:32:35