The document provides 11 powerful JavaScript tips and best practices for programmers, including using short-circuit evaluation to set default values, immediately invoked function expressions to avoid polluting the global namespace, and splice instead of delete to remove array items without leaving undefined holes.
Slides from my "Object-oriented JavaScript" presentation at CSDN (China Software Developers Network), Beijing, December 2008
JavaScript is the programming language of the web. It can dynamically manipulate HTML content by changing element properties like innerHTML. Functions allow JavaScript code to run in response to events like button clicks or timeouts. JavaScript uses objects and prototypes to define reusable behaviors and properties for objects. It is an important language for web developers to learn alongside HTML and CSS.
Functions being first-class citizens in JavaScript offers developers a tremendous amount power and flexibilty. However, what good is all this power if you don't know how to harness it? This talk will provide a thorough examination of JavaScript functions. Topics that will be covered in this talk are: * Functions are objects * Execution Context and the Scope Chain * Closures * Modifying Context * The Various Forms of Functions. Attendees will leave this talk understanding the power of JavaScript functions and the knowledge to apply new techiques that will make their JavaScript cleaner, leaner and more maintainable.
JavaScript has some stunning features like Closures, Prototype etc. which can help to improve the readability and maintainability of the code. However, it is not easy for inexperienced developer to consume and apply those features in day to day coding. The purpose of the presentation ‘Advanced JavaScript’ is to help a reader easily understand the concept and implementation of some advanced JavaScript features.
This document provides an overview of basic JavaScript examples and concepts. It covers topics such as writing JavaScript code, variables, conditional statements, functions, loops, events, and error handling. For each topic, it provides short code snippets to demonstrate the concept. It concludes by referencing W3Schools as a resource and thanking the reader.
In JS: CLASS <=> Constructor FN new FN() => FN() { this } FN = CLASS (FN = FN, FN = DATA) Objects Prototype / __proto__ Inheritence Rewriting / Augmenting built in objects
The document provides an overview of JavaScript, covering what it is, its basics, functions, objects, prototypes, scope, asynchronous JavaScript, JSON, debugging tools, performance, events, error handling, and the future of JavaScript. It discusses that JavaScript is an object-oriented scripting language used in web pages that is not tied to specific browsers but makes use of the DOM, BOM, and ECMAScript standards. It also summarizes some of JavaScript's core features like functions, objects, prototypes, and more.
This talk takes a deep dive into asynchronous programming patterns and practices, with an emphasis on the promise pattern. We go through the basics of the event loop, highlighting the drawbacks of asynchronous programming in a naive callback style. Fortunately, we can use the magic of promises to escape from callback hell with a powerful and unified interface for async APIs. Finally, we take a quick look at the possibilities for using coroutines both in current and future (ECMAScript Harmony) JavaScript.
This document provides an introduction to JavaScript including: - JavaScript is an object-oriented scripting language that is a dialect of ECMAScript. - It was originally designed to add interactivity to HTML pages through dynamic HTML, reacting to events, and data validation. - JavaScript is now heavily used in AJAX-based sites to asynchronously retrieve and display data without reloading pages. - The document discusses JavaScript compatibility issues and provides examples of basic JavaScript concepts like variables, comparisons, repetition, and popup boxes.
This document discusses several common JavaScript design patterns including Singleton, Factory, Module, Decorator, Command, and Observer patterns. It provides descriptions and code examples for each pattern. The Singleton pattern ensures a class only has one instance and provides a global access point. Factory patterns are used for object creation. The Module pattern provides private and public encapsulation for classes. The Decorator pattern attaches additional responsibilities to objects dynamically. The Command pattern encapsulates requests as objects, and the Observer pattern allows objects to watch other objects for changes.
1. The document discusses JavaScript concepts like scope, closures, context, and object-oriented programming techniques like constructors, methods, and inheritance. 2. It provides examples of how to create public and private methods, and "privileged" methods that have access to private values and methods. 3. The document shows how to dynamically generate classes at runtime based on properties passed to a constructor using these JavaScript concepts.
Anonymous functions allow functions to be defined and called without a name. JavaScript functions are first-class objects that can be treated like any other object. This allows functions to be defined anonymously and immediately called by wrapping the function definition in parentheses and adding another set of parentheses to call it. For example, (function(){ return "Hello World"; })(); defines and immediately calls an anonymous function without needing to assign it a name.