background preloader

Classical Inheritance in JavaScript

Classical Inheritance in JavaScript
Douglas Crockford www.crockford.com And you think you're so clever and classless and free — John Lennon JavaScript is a class-free, object-oriented language, and as such, it uses prototypal inheritance instead of classical inheritance. This can be puzzling to programmers trained in conventional object-oriented languages like C++ and Java. JavaScript's prototypal inheritance has more expressive power than classical inheritance, as we will see presently. But first, why do we care about inheritance at all? The second reason is code reuse. To demonstrate this, we will introduce a little sugar which will let us write in a style that resembles a conventional classical language. Classical Inheritance First, we will make a Parenizor class that will have set and get methods for its value, and a toString method that will wrap the value in parens. The syntax is a little unusual, but it is easy to recognize the classical pattern in it. So now we can write As you would expect, myString is "(0)". Sugar

http://www.crockford.com/javascript/inheritance.html

Related:  javascript

Coder's Block Blog / Motion Detection with JavaScript I recently gave a talk at RevolutionConf about writing a motion detecting web app with JavaScript. This is basically that talk, but in blog form. Live demos and all the source code are available at the end of this article. The Premise I wanted to see what my pets do when I’m away. But I didn’t want a continuous live stream, since that would be pretty boring (they sleep a lot). 5 Must-Reads on JavaScript Inheritance By Karthik Viswanathan Do you know inheritance in JavaScript? Do you truly understand how it works? Are you aware that JavaScript uses a prototypal inheritance scheme that is often disfavored or disliked? Have you used a script on the web to adapt this scheme to classical inheritance?

JavaScript: The World's Most Misunderstood Programming Language Douglas Crockford www.crockford.com JavaScript, aka Mocha, aka LiveScript, aka JScript, aka ECMAScript, is one of the world's most popular programming languages. Virtually every personal computer in the world has at least one JavaScript interpreter installed on it and in active use. JavaScript's popularity is due entirely to its role as the scripting language of the WWW.

Getting Started Guide NativeScript Getting Started Guide Welcome to the NativeScript Getting Started Guide. In this tutorial you'll use NativeScript, a cross-platform JavaScript framework for building native mobile apps, to build an iOS and Android app from scratch. You can start by watching the video walkthrough below, or by jumping straight into the hands-on tutorial. What is NativeScript? NativeScript is a free and open source framework for building native iOS and Android apps using JavaScript and CSS. Simple JavaScript Inheritance I’ve been doing a lot of work, lately, with JavaScript inheritance – namely for my work-in-progress JavaScript book – and in doing so have examined a number of different JavaScript classical-inheritance-simulating techniques. Out of all the ones that I’ve looked at I think my favorites were the implementations employed by base2 and Prototype. I wanted to go about extracting the soul of these techniques into a simple, re-usable, form that could be easily understood and didn’t have any dependencies. Additionally I wanted the result to be simple and highly usable. Here’s an example of what you can do with it:

Javascript: Stop Fighting It I recently came to the realization that I've been fighting Javascript too much. It's because I've been going against the grain with it. It's like trying to force the OO paradigm in a functional language or the opposite. You might say that I've been treating Javascript like an OO language and you would be right. But, I've been forcing my class-based thinking on it and it's been not so nice. I've been reacquainting myself with Self and Io again.

11 Free jQuery CSS3 Navigation Menu Plugins These days, jQuery Navigation menus are more than plain texts with links on it. With the command of jQuery, it can transform the menu of a web site into a dynamic menu. Despite the fact that CSS3 can now be utilized to make dynamic menu, still, the query includes more functionality to the menus. Aside from the element functionalities, the design should likewise be considered. Because of audience your site would perhaps see it for the first time they visit your website. What ASP.NET Developers Should Know About JavaScript JavaScript – It's beat up, put down, shrugged off and kicked around. Cursed by the web browser's inconsistency yet blessed by a pervasive ubiquity -it's a technology many try to disregard even when its potential is something few can ignore. If you want to write an interactive application for the web today, then you'll need some JavaScript code on your side. This article approaches JavaScript from the perspective of an ASP.NET developer who is comfortable with the paradigms and patterns of either C# or Visual Basic. The article doesn't look at how to use JavaScript from ASP.NET exactly, but it does look at why JavaScript is so different from the two languages we commonly use with the .NET CLR.

Advanced Web Applications With Object-Oriented JavaScript Recently I interviewed a software developer with five years experience in developing Web applications. She’d been doing JavaScript for four and a half years, she rated her JavaScript skill as very good, and—as I found out soon after—she actually knew very little about JavaScript. I didn’t really blame her for that, though. Infographic: The Entire JavaScript Language in One Single Image Chinese-based developer Yusheng, has created a nice graphic that assembles the entire JavaScript programming syntax into one single all-encompassing image. Regardless of what the TIOBE Index says, JavaScript, and not Java, is the hottest programming language right now. This popularity was won very hard, having to fight through a period where the language seemed to have stood still with no new features being released for a period of four years. Despite this, developers rushed to the language, mainly due to the technologies being developed on top of it, and more specifically Node.js. If today some of you want to delve into JavaScript in the upcoming future, there are many tutorials you can find online, all great resources for learning the language's fundamentals from the ground up in a matter of days. But if things are constantly escaping your memory, Chinese-based developer Yusheng has assembled a nice mind map of the entire JavaScript language syntax, complete with code examples.

Related: