Today's Question:  What does your personal desk look like?        GIVE A SHOUT

SEARCH KEYWORD -- setInterval

  The evolving history of asynchronous operation in JavaScript

JavaScript is single threaded, it means there would be only one task running at any point of time. But this would slow down the overall program execution if there is long running task, hence asynchronous task execution is desired in complex cases. To achieve asynchronous task execution, there are a few options introduced in JavaScript. setTimeout/setInterval Event Promise Async/Await setTimeout/setInterval is one of the first mechanisms introduced in JavaScript to simulate asynchronous operati...

   JAVASCRIPT,ASYNC,PROMISE,AWAIT     2019-11-09 08:21:56

  JavaScript tutorial - Creating time delays

There are two ways of creating time delays with JavaScript. The first is more simple and will simply wait for a specified amount of time before executing a function. The second does the same but will repeatedly execute the function. Note, many browsers have a minimum delay length of between 25 and 75 ms, with some of the fastest browsers having a minimum delay of about 3 ms. If a shorter delay is specified, the actual delay will be the minimum delay length. Even with higher numbers, the delay i...

   JavaScript,Time delay,setTimeout,setInterval     2012-04-13 07:17:46

  Cool HTML5 matrix effect

Do you still remember the movie The Matrix? Do you still remember the cool matrix effect in that movie? How is that effect achieved? Shaun Dunne shared a piece of HTML5 code which displays a cool matrix effect. The matrix demo can be found here. Below is the code which he achieves this effect: with var s = window.screen; var width = q.width = s.width; var height = q.height = s.height; var letters = Array(256).join(1).split(''); var draw = function () { q.getContext('2d').fillStyle='rgba(0,0,...

   Matrix,HTML5     2013-08-14 08:03:34

  Simple Animation in the HTML5 Canvas Element

HTML5 is generating all kinds of buzz these days. Some of the buzz is about HTML5 being a replacement for Adobe’s Flash. I don’t think it’s there yet but it’s certainly on the way to changing the way content is presented on the web. This is a description of a very simple animation in an HTML5 canvas element. It is coded for readability and not for optimized operation. We’ll add a canvas element to a web page and then use javascript to draw on it. We will...

   HTML5,Canvas,Animation,Sample code     2011-07-01 10:20:08

  IE ActiveX(”htmlfile”) Transport, Part II

In my last post I discussed using the ActiveX(”htmlfile”) technique to provide a usable streaming transport in Internet Explorer. The solution I provided will work, but since writing the last article I’ve made significant progress in understanding why IE behaves the way it does with respect to the streaming transport. The previous solution amounted to creating an array of messages, pushing messages on that array from the htmlfile iframe, and popping messages off of the array i...

   IE,Http,Streaming,htmlfile,Transport,Act     2011-09-05 04:07:02

  JavaScript interview questions

This post will cover the JavaScript questions I have encountered and have seen during my programming career. They will mainly focus on vanilla JavaScript though there are lots of excellent frameworks out there and many people are using them in their daily work. this keyword this keyword is an very important but easy to confuse concept in JavaScript since it is always referring to the calling object of the function. 1. What will be the output of below code snippet? function User(name) { this....

   JAVASCRIPT,ALGORITHM,THIS,CLOSURE     2019-03-09 07:05:46

  Turn browser into notepad with one line of code

This is the code shared by Jose on codewall. When you type data:text/html,   into the address bar of the browser and press enter, the browser will turn into a notepad which you can edit. Why it works? This uses Data URI’s format and it tells the browser to render HTML. But contenteditable is a property of HTML5, so this can only work in the web browser which supports this property. Here are some interesting contents. Some people make some changes to the code encouraged by the ide...

   HTML5, Browser editor     2013-01-30 04:20:54

  JavaScript efficiency catch up

JavaScript is a very flexible language, we can write JavaScript code freely with various styles, different kinds of codes will have different execution efficiency. Here we summarize some tips we get from our development. Efficiency of JavaScript itself JavaScript has execution context chain, closures, prototype inheritance, eval etc. It brings us some magic features, but it also introduces the performance issue, if we don't use them properly, it will affect the codes execution efficiency. 1. Glo...

   JavaScript,efficiency,event delegation,eval     2013-04-02 04:08:46

  HTTP Streaming and Internet Explorer

In early 2006, Alex Russell posted about a neat hack that the Google Talk team in Gmail use to support Comet in Internet Explorer, a trick which works as far back as IE 5.01. What great news! A reliable way to stream Comet messages to Microsoft’s browsers. If only it were that easy. I have not been alone in the following findings: after connecting the htmlfile ActiveX object as a streaming Comet transport to my Comet server, everything works perfectly for a few messages, but then abruptly...

   IE,Streaming,JavaScript,htmlfile,ActiveX     2011-09-05 04:05:23

  HTML5 Web Worker

Web Worker is a JavaScript multithreading solution provided by HTML5. we can put some compute intensive codes into Web Worker and it will not hang the user interface. 1. How to use Web Worker Web Worker's basic mechanism is to use Worker to load a JavaScript file to create a new thread in JavaScript's main thread. It will not block other thread's execution and will provide a data exchange interface between main thread and new thread : postMessage() and onmessage. Let's look at an example: //work...

   JavaScript,HTML,Web Worker     2012-12-02 06:25:00

RECENT