Frequently Misunderstood JavaScript Concepts. This is a complete "reprint" of Appendix B from my book,Closure: The Definitive Guide. Even though my book was designed to focus on Closure rather than JavaScript in general, there were a number of pain points in the language that I did not think were covered well in other popular JavaScript books, such as JavaScript: The Good Parts or JavaScript: The Definitive Guide. So that the book did not lose its focus, I relegated this and my essay, "Inheritance Patterns in JavaScript," to the back of the book among the appendices. However, many people have told me anecdotally that Appendix B was the most valuable part of the book for them, so it seemed like this was worth sharing more broadly in hopes that it helps demystify a language that I have enjoyed so much.
This book is not designed to teach you JavaScript, but it does recognize that you are likely to have taught yourself JavaScript and that there are some key concepts that you may have missed along the way. Alert(map["[object Object]"]); Object Oriented JavaScript using Prototype Object - Saurabh Nijhawan. For updated version of the article please visit www.agnosticdevs.com Object Oriented JavaScript using Prototype Object This document describes the benefit of using Object Oriented Approach in JavaScript Codes and implements Calendar Management component having a few functions like Add/Edit/Delete Events on selected date.
As we all know Object Oriented Programming (OOP) is a major part and practice for reusability. Most of the times even if we are following standard ways to code on server-side, we just forget or omit about client side structure of application. As a result it becomes hectic to manage later, when application is modified to release a newer version of the same. As per my personal experience on the same, I found prototyping and object oriented JavaScript a perfect solution. Note: To understand the logic completely, you must have clear understanding on concepts like, Inheritance, constructors, Classes and objects. What is Prototype? For Example:- JavaScript How it works: Example 1:
Prototype JavaScript Framework | Defining classes and inheritance. In early versions of Prototype, the framework came with basic support for class creation: the Class.create() method. Until now the only feature of classes defined this way was that the constructor called a method called initialize automatically. Prototype 1.6.0 now features a richer class system that's backward-compatible and adds some new features. The cornerstone of class creation in Prototype is still the Class.create method. If you have legacy Prototype code, your class-based code will continue to work as before, but now you don't have to work with prototypes directly or use Object.extend to copy properties around.
Example Suppose you have legacy Prototype class-based code that looks like htis: Observe the direct interaction with class prototypes and the clumsy inheritance technique using Object.extend. This has changed for the better. You can see how both class and subclass definitions are shorter because you don't need to hack their prototypes directly anymore. How to mix-in modules <? Object Oriented JavaScript using Prototype Object - Saurabh Nijhawan. Javascript Closures. Introduction Closure A "closure" is an expression (typically a function) that can have free variables together with an environment that binds those variables (that "closes" the expression). Closures are one of the most powerful features of ECMAScript (javascript) but they cannot be property exploited without understanding them.
They are, however, relatively easy to create, even accidentally, and their creation has potentially harmful consequences, particularly in some relatively common web browser environments. To avoid accidentally encountering the drawbacks and to take advantage of the benefits they offer it is necessary to understand their mechanism. This depends heavily on the role of scope chains in identifier resolution and so on the resolution of property names on objects. The simple explanation of a Closure is that ECMAScript allows inner functions; function definitions and function expressions that are inside the function bodes of other functions. Assignment of Values Finally:- An. Best of Fluent 2012: /Reg(exp){2}lained/: Demystifying Regular Expressions. You Don’t Know Anything About Regular Expressions: A Complete Guide. Regular expressions can be scary...really scary. Fortunately, once you memorize what each symbol represents, the fear quickly subsides. If you fit the title of this article, there's much to learn!
Let's get started. The key to learning how to effectively use regular expressions is to just take a day and memorize all of the symbols. This is the best advice I can possibly offer. Sit down, create some flash cards, and just memorize them! Here are the most common: . Yep - it's not fun, but just memorize them. You can be certain that you'll want to rip your hair out at one point or another when an expression doesn't work, no matter how much it should - or you think it should!
The next step is to learn how to actually use these symbols! In this final section, we'll review a handful of the most important JavaScript methods for working with regular expressions. This one accepts a single string parameter and returns a boolean indicating whether or not a match has been found. Thanks for reading! Script Junkie | Prototypes and Inheritance in JavaScript. Forget everything you know about object-oriented programming. Instead, I want you to think about race cars. Yes – race cars. Recently I was watching the 24 Hours of Le Mans –a popular racing event in France.
The fastest cars in the race are the Le Mans Prototypes. Although these cars are built by car manufacturers like Audi and Peugeot, they are not cars you’ll see on the streets and highways of your home town. Manufacturers put an enormous amount of money into researching, engineering, and building these prototype cars, and the engineers are always trying to find an edge. You could say mainstream cars inherit technology from racing prototypes. And now we’ve set the mood to talk about prototypes and inheritance in JavaScript. Of Objects and Classes JavaScript is full of objects, and I mean objects in the classical sense.
Var myArray = [1, 2]; myArray.push(3); myArray.reverse(); myArray.pop(); var length = myArray.length; The question is – where does a method like push come from? Figure 1.