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3 ways to define a JavaScript class

3 ways to define a JavaScript class
Introduction JavaScript is a very flexible object-oriented language when it comes to syntax. In this article you can find three ways of defining and instantiating an object. It's important to note that there are no classes in JavaScript. 1. This is probably one of the most common ways. function Apple (type) { this.type = type; this.color = "red"; this.getInfo = getAppleInfo; } function getAppleInfo() { return this.color + ' ' + this.type + ' apple'; } To instantiate an object using the Apple constructor function, set some properties and call methods you can do the following: var apple = new Apple('macintosh'); apple.color = "reddish"; alert(apple.getInfo()); 1.1. In the example above you see that the method getInfo() of the Apple "class" was defined in a separate function getAppleInfo(). function Apple (type) { this.type = type; this.color = "red"; this.getInfo = function() { return this.color + ' ' + this.type + ' apple'; }; } 1.2. 2. apple.color = "reddish"; alert(apple.getInfo()); 3.

css Zen Garden: The Beauty in CSS Design Developing Backbone.js Applications - By Addy Osmani (@addyosmani) Available free for open-source reading below or for purchase via the O'Reilly store. Pull requests and comments always welcome. Prelude Not so long ago, “data-rich web application” was an oxymoron. Today, these applications are everywhere and you need to know how to build them. Traditionally, web applications left the heavy-lifting of data to servers that pushed HTML to the browser in complete page loads. Think of the Ajax shopping cart which doesn’t require a refresh on the page when adding an item to your basket. The rise of arbitrary code on the client-side which can talk to the server however it sees fit has meant an increase in client-side complexity. Thankfully, there are a growing number of JavaScript libraries that can help improve the structure and maintainability of your code, making it easier to build ambitious interfaces without a great deal of effort. Target Audience Acknowledgements Credits Target Version Reading What Is MVC? What is Backbone.js? <! Views

Inversion of Control Containers and the Dependency Injection pattern In the Java community there's been a rush of lightweight containers that help to assemble components from different projects into a cohesive application. Underlying these containers is a common pattern to how they perform the wiring, a concept they refer under the very generic name of "Inversion of Control". In this article I dig into how this pattern works, under the more specific name of "Dependency Injection", and contrast it with the Service Locator alternative. The choice between them is less important than the principle of separating configuration from use. One of the entertaining things about the enterprise Java world is the huge amount of activity in building alternatives to the mainstream J2EE technologies, much of it happening in open source. Underlying these containers are a number of interesting design principles, things that go beyond both these specific containers and indeed the Java platform. Components and Services A Naive Example class MovieLister... Inversion of Control

Object-Oriented Programming with JavaScript, Part I: Inheritance: Inheritance through Functions - Doc JavaScript - Webreference.com Object-Oriented Programming with JavaScript, Part I: Inheritance Inheritance through Functions Although JavaScript does not support an explicit inheritance operator, you can implement inheritance in other ways. There are two different ways to establish a hierarchy of classes in JavaScript. The first method to create an object as a subclass of another object, is to call the superclass constructor function inside the subclass object definition. function superClass() { this.bye = superBye; this.hello = superHello; } function subClass() { this.inheritFrom = superClass; this.inheritFrom(); this.bye = subBye; } function superHello() { return "Hello from superClass"; } function superBye() { return "Bye from superClass"; } function subBye() { return "Bye from subClass"; } function printSub() { var newClass = new subClass(); alert(newClass.bye()); alert(newClass.hello()); } Convince yourself that it is working correctly. this.inheritFrom = superClass; this.inheritFrom(); Let's take another example.

Learning Javascript with Object Graphs HEADS UP! This article was written for an older version of node. More up-to-date information may be available elsewhere. One of the secrets to being a super effective JavaScript developer is to truly understand the semantics of the language. This article will explain the basic elemental parts of JavaScript using easy to follow diagrams. References Everywhere A variable in JavaScript is simply a label that references a value in memory somewhere. Local Variables In the following example, we will create four local variables in the top-level scope and point them to some primitive values: variables.js // Let's create some local variables in the top scopevar name = "Tim Caswell";var age = 28;var isProgrammer = true;var likesJavaScript = true;// Test to see if the two variables reference the same valueisProgrammer === likesJavaScript; Notice that the two boolean variables point to the same value in memory. The outer box represents the outermost closure scope. Objects and Prototype Chains objects.js

Command Line API Reference The Command Line API is a collection of functions for performing common tasks with the Chrome Developer Tools. These include convenience functions for selecting and inspecting elements in the DOM, stopping and starting the profiler, and monitoring DOM events. This API complements the Console API, the Command Line API is only available from within the console itself. Returns the value of the most recently evaluated expression. In the next example, the evaluated expression is a call to the $$() method, which returns an array of elements that match the CSS selector. Dev Tools remembers the last five DOM elements (or JavaScript heap objects) that you've selected in the tab (or Profiles panel). In the following example, an element with the ID gc-sidebar is selected in the Elements tab. The image below shows the gc-content element selected in the same page. The following example saves a reference to the first <img> element in the document and calls displays its src property: $('img').src;

Inversion of Control Containers and the Dependency Injection pattern In the Java community there's been a rush of lightweight containers that help to assemble components from different projects into a cohesive application. Underlying these containers is a common pattern to how they perform the wiring, a concept they refer under the very generic name of "Inversion of Control". In this article I dig into how this pattern works, under the more specific name of "Dependency Injection", and contrast it with the Service Locator alternative. The choice between them is less important than the principle of separating configuration from use. One of the entertaining things about the enterprise Java world is the huge amount of activity in building alternatives to the mainstream J2EE technologies, much of it happening in open source. A lot of this is a reaction to the heavyweight complexity in the mainstream J2EE world, but much of it is also exploring alternatives and coming up with creative ideas. Components and Services A Naive Example class MovieLister...

Inheritance and the prototype chain - JavaScript JavaScript is a bit confusing for developers experienced in class-based languages (like Java or C++), as it is dynamic and does not provide a class implementation (although the keyword class is a reserved keyword and cannot be used as a variable name). When it comes to inheritance, JavaScript only has one construct: objects. Each object has an internal link to another object called its prototype. That prototype object has a prototype of its own, and so on until an object is reached with null as its prototype. null, by definition, has no prototype, and acts as the final link in this prototype chain. While this is often considered to be one of JavaScript's weaknesses, the prototypal inheritance model is in fact more powerful than the classic model. Inheritance with the prototype chain Inheriting properties JavaScript objects are dynamic "bags" of properties (referred to as own properties) and each one has a link to a prototype object. In this example, someObject. Inheriting "methods"

Raphaël—JavaScript Library

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