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  Run code with multiple files in the same main package in GoLang

To run a GoLang program, there needs to be a main() function defined. In some cases when developing some demo program which has multiple files and just wanna put them in the same main package and this folder is not in GOPATH, how to run the program? Let's say we have following folder structure where the main() function is defined in main.go. If you just run below command, it would fail to start to run the program and gives some error if some struct is defined in other files and being used. PS D...

   EXECUTABLE,GOLANG,MAIN PACKAGE,MULTIPLE FILE     2021-05-15 10:20:10

  <=> operator in MySQL

Have you ever seen "<=>" in a SQL query while using MySQL? Does it mean less and equals to and greater than? Actually if you consider it as the union of <= and =>, great, you are close to it. This is one form of equal operator in MySQL, it has the similar meaning to the = operator with some subtle difference. According to MySQL documentation, <=> is NULL-safe equal. This operator performs an equality comparison like the = operator, but returns 1 rather than NULL if both operand...

   MySQL,NULL safe,<=>     2014-03-24 06:23:22

  + operation on JavaScript objects

In JavaScript, there are two types of values: primitive and object. Primitives consist undefined, null, boolean, number and string. Other values such as array and function are objects. When applying + operation on different type of values, there would be three kinds of type conversion. Primitive conversion Number conversion String conversion There three type conversions have corresponding abstract operations in JavaScript: ToPrimitive(), ToNumber(), ToString(). For number additi...

   JAVASCRIPT,PROGRAMMING     2018-10-12 22:19:12

  Understand Virtual DOM

With the popularity of React, the internals and implementation of Virtual DOM has becoming top discussed topic in tech communities and interviews. This post will give an introduction of Virtual DOM and how to implement a simple Virtual DOM logic. How to understand Virtual DOM In early days, front end developers would update a webpage view based on the data status change(usually after making AJAX call). But it brings performance penalties when there is frequent update as it would cause page reflo...

   JAVASCRIPT,DOM,VIRTUAL DOM     2019-12-07 23:43:04

  JavaScript as a First Language

At Khan Academy we've been investigating teaching Computer Science to students in some new and interesting ways. The most interesting aspect of which is that we're likely going to be teaching them JavaScript as their first language. We're in a very unique position as we're primarily aiming to teach students who've been through our previous math and science-centric curriculum. Because of this we can create some rather compelling exercises and projects that never would've been feasible other...

   JavaScript,Learning,First language,Inheritence,Prototype     2011-12-23 07:53:45

  File upload once again

File upload is one of the oldest operation of web design. After 20 years, it's still has no big change, difficult to handle, lack of interaction and poor user experience. Web developers have thought many methods to improve the experience of uploading file in web apps, they developed various plugins based on different JavaScript libraries. However, because of the difference among different web browsers, there is no common interface which makes these plugins work properly or easily on all web brow...

   Web design, File upload, Asynchronous,HTML5     2012-09-02 11:52:21

  How to play with cross domain request

What is cross domain request In simple, cross domain request is to request resource from other domain in one domain. Note, the "other domain" doesn't just mean domain name only, it includes much more. If the protocol, domain name, port is not the same, two domains will be considered different.  Below example describes what is considered as different domain. http://www.a.com/a.jshttp://www.a.com/b.js               # Same domainhttp://www.a.com/lab/a.js &nb...

   FRONT END,JSONP,CROSS DOMAIN,CROSS ORIGIN,CORS,DOCUMENT.DOMAIN,WINDOW.NAME     2016-11-06 00:48:54

  Method chaining and lazy evaluation in Ruby

Method chaining has been all the rage lately and every database wrapper or aything else that’s uses queries seems to be doing it. But, how does it work? To figure that out, we’ll write a library that can chain method calls to build up a MongoDB query in this article. Let’s get started! Oh, and don’t worry if you haven’t used MongoDB before, I’m just using it as an example to query on. If you’re using this guide to build a querying library...

   Ruby,Method chaining,Lazy evaluation,Implementation     2011-11-29 08:51:17

  Ruby WinRM undefined method `split' for nil:NilClass

WinRM service is a service provided by Windows to enable remote access a Windows system. It is similar to what SSH is for *nix. And it is frequently used in applications which want to automate process or accessing remote Windows system and perform actions on them. Ruby also provided the WinRM gem which is an implementation of the WinRM service.  When using WinRM gem, one may often want to use :negotiate as the transport protocol for authentication. This transport will negotiate using d...

   RUBY,WINRM,INIT_AUTH,PROXY     2017-03-08 02:21:09

  Three ways to define class in JavaScript

In object oriented programming, class is the template of object, it defines the properties and methods of a group of objects. Unfortunately, JavaScript doesn't support class, but we can have some workarounds to simulate class.1. Constructor functionThis is the classical approach, it is also the approach mentioned in many text books. It uses the constructor function to simulate class and it uses the keyword this to represent the object internally.function Cat() {　　this.name = "Kelly...

   JavaScript,Class,Method,Private,Inheritance     2012-07-09 11:59:51

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