SEARCH KEYWORD -- JavaScript log


  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

  Service discovery with etcd

In previous post, we have talked about etcd and its usage. This post we will cover how to implement server discovery with etcd. Service discovery is to solve one of the most commonly seen scenarios in distributed system where how to find the corresponding target service to talk to. In short, it is to find some server which one can talk to based on some service name. A complete service discovery system include below three key functions: Service registration: A service must register itself to so...

   ETCD,SERVICE DISCOVERY,DEMO,TUTORIAL     2021-03-08 05:36:29

  Regular expression to get html meta description

When we need to process a HTML page source code, we often need to retrieve the meta description of the page besides the links in the page. This description is usually located in <meta> tag of a HTML page. The meta description is very useful for search engine index. How can we retrieve the meta description? If we use a regular expression, we can easily get the meta description. In JavaScript, the regular expression looks like : var pattern = /<meta.*?name="description".*?content="(.*?)"....

   Regular expression,meta description,HTML,JavaScript     2012-07-03 10:09:20

  Commonly used AJAX frameworks

Have you ever wondered to design your website like desktop applications? Fortunately, with AJAX we can achieve this. By using AJAX, we no need to refresh the whole page when we just want to update a portion of a website such as the weather information or news panel. This makes our web apps look like desktop applications and bring good user experience to our visitors. You can create an XMLHttpRequest object every time when you want to initialize an AJAX call, unfortunately you may need repeat eve...

   AJAX,framework,jQuery,Dojo,YUI     2012-06-27 04:40:05

  Which programming language should I learn first?

Recently I saw somebody asked a question in a forum, the question is "Which programming language should I learn first?". Then someone answered this question. His answer:Depends. To program in an expressive and powerful language: PythonTo get a website up quickly: PHPTo mingle with programmers who call themselves “rockstars”: Ruby.To really learn to program: C.To achieve enlightenment: Scheme.To feel depressed: SQLTo drop a chromosome: Microsoft Visual BasicTo get a guaranteed, m...

   Programming language,Learn,JavaScript,C     2012-04-29 02:59:17

  Run JavaScript in GoLang

In some cases, there might be some JavaScript code needs to be ran in a GoLang project. Fortunately, there are a few libraries which support running JavaScript in GoLang. The most famous one would be v8. This is a Go API for the famous v8 JavaScript engine originally developed for the Chrominum project and the foundation of NodeJS. In this post, we will show some simple steps to get v8 working in a GoLang program on MacOS. First you need to install the package so that you can import it. Run...

   GOLANG,JAVASCRIPT,V8     2019-05-16 07:40:38

  JavaScript programming style

Douglas Crockford is a JavaScript expert, he is the inventor of JSON. In November 2011 he made a speech "Youtube", during the speech he talked about what JavaScript programming style is.I recommend this speech to everyone, it not only helps you learn JavaScript but also make you enjoying because Crockford is very humorous and he made audience laugh frequently.Next I will summarize JavaScript programming style according to this speech and his article code convention. The so-called programming ...

   JavaScript, programming style,Curly braces,Equal     2015-10-14 10:16:44

  Calculating Token Count for Claude API Using Go: A Step-by-Step Guide

When working with large language models like Claude from Anthropic, understanding how many tokens your input consumes is essential for managing costs and optimizing performance. In this blog, we’ll explore how to calculate token counts for a given input using Go. We’ll use Anthropic’s count_tokens API endpoint, which provides a straightforward way to determine token usage. Prerequisites Before diving in, ensure you have: A working Go environment (installation guide). An Anthro...

   CLAUDE,GO,GOLANG,TOKEN CALCULATION,GUIDE,EXAMPLE     2024-12-23 22:25:29

  JS code to check different mobile devices

Today I come across a code snippet which uses JavaScript to check different mobile devices and then loads different CSS files accordingly. As we know that there are mobile devices with different screen sizes, it's always troublesome for web developers to develop cross browser and cross device compatible codes. Hope this one can help those who develop web apps on mobile devices. // Check whether it's a mobile device // wukong.name 20130716 if(/AppleWebKit.*Mobile/i.test(navigator.userAgent) || (...

   JavaScript,Mobile device,Detection     2013-11-28 05:25:10

  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

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