Google JS Test is a JavaScript unit testing framework that runs on the V8 JavaScript Engine, the same open source project that is responsible for Google Chrome’s super-fast JS execution speed. Google JS Test is used internally by several Google projects, and we’re pleased to announce that it has been released as an open source project.Features of Google JS Test include:Extremely fast startup and execution time, without needing to run a browser.Clean, readable output in the case of both passing and failing tests.An optional browser-based test runner that can simply be re...

How to find the greatest common divisor betweentwo integers? We may encounter this problem frequently in interviews or otheroccasions.Anefficient metho to find gcd is the Euclideanalgorithm, whichuses the divisionalgorithm incombination with the observation that the gcd of two numbers also divides theirdifference: divide 48 by 18 to get a quotient of 2 and a remainder of 12. Thendivide 18 by 12 to get a quotient of 1 and a remainder of 6. Then divide 12 by6 to get a remainder of 0, which means that 6 is the gcd. Formally, it could bewritten asgcd(a,0)= agcd(a,b)= gcd(b...

In secondary school, we have learned permutation. Basically, for n numbers, the number of permutations for these n numbers can be calculated to n! which is called 'n factorial'. But to display all the permutations on the screen, we need to use a recursive function. The problem is how to write this function. Next I write a program to display the permutations for n numbers with JavaScript. First, we need to understand that from these n numbers, we can first take any one number from it, and the (n-1) numbers remaining has the similar property as the n numbers, we need to find the permutation...

Node.js is all the buzz at the moment, and makes creating high performance, real-time web applications easy. It allows JavaScript to be used end to end, both on the server and on the client. This tutorial will walk you through the installation of Node and your first “Hello World” program, to building a scalable streaming Twitter server.What is Node.js?JavaScript has traditionally only run in the web browser, but recently there has been considerable interest in bringing it to the server side as well, thanks to the CommonJS project. Other server-side JavaScript environments...

Deleting an item from an array is easy using JavaScript’s built-in method splice(). However, if you are somewhat new to scripting, simply knowing about splice does not help you remove a certain item from an array. This article will solidly state the solution to this dilemma.If you want to remove a specific item from your array, you will simply use a basic loop and a conditional check with the splice()method.Here is a breakdown of what we will do in 3 easy steps, so that you can implement this solution yourself later.The Three Step ProcessSetup a basic ‘forâ€...

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 fails. The connection is closed by the browser with the server-side error “Connection reset by...

Following on from his previous article, David Chisnall explores JavaScript as an example of prototype-based object orientation. In this article, he shows how it's possible to implement more complex object models on top of this simple abstraction.My previous article, Prototypes and Object Orientation, considered the differences between class-based and prototype-based object orientation. In this article, we'll look in a bit more detail at the workings of the JavaScript object model, since it's currently the most popular prototype-based object-oriented language.What's New?In Self, you create...

In today's post, we'll be taking a look at how you can use CSS3 transitions to power your application's animations with jQuery's .animate() method as a fallback where transitions aren't supported. The benefit of transitions is that unlike JavaScript based animations, they're hardware accelerated in certain browsers and mobile devices, resulting in a potentially smoother overall animation than you would normally experience. In a lot of cases your code will work seamlessly with the solutions presented today, so the effort involved in applying them is minimal. Before we get started, if ...