Download or read book TypeScript Quickly written by Anton Moiseev and published by Simon and Schuster. This book was released on 2020-02-10 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary TypeScript is JavaScript with an important upgrade! By adding a strong type system to JavaScript, TypeScript can help you eliminate entire categories of runtime errors. In TypeScript Quickly, you’ll learn to build rock-solid apps through practical examples and hands-on projects under the expert instruction of experienced web developers Yakov Fain and Anton Moiseev. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. About the technology Strong typing can eliminate nearly all errors caused by unanticipated data values. With TypeScript, an enhanced version of JavaScript, you can specify types and type annotations so your code is easier to read and far less likely to fail at runtime. And because the core of TypeScript is standard JavaScript, it runs on all major browsers and can be used with frameworks like Angular, Vue, and React. About the book TypeScript Quickly teaches you to exploit the benefits of types in browser-based and standalone applications. In this practical guide, you’ll build a fascinating blockchain service app that takes you through a range of type-sensitive programming techniques. As you go, you’ll also pick up valuable techniques for object-oriented programming with classes, interfaces, and advanced features such as decorators and conditional types. What's inside Mastering TypeScript syntax Using TypeScript with JavaScript libraries Tooling with Babel and Webpack Developing TypeScript apps using Angular, React, and Vue About the reader For web developers comfortable with JavaScript and HTML. About the author Yakov Fain and Anton Moiseev are experienced web developers. They have authored two editions of Manning’s Angular Development with TypeScript. Table of Contents: PART 1 MASTERING THE TYPESCRIPT SYNTAX 1 ¦ Getting familiar with TypeScript 2 ¦ Basic and custom types 3 ¦ Object-oriented programming with classes and interfaces 4 ¦ Using enums and generics 5 ¦ Decorators and advanced types 6 ¦ Tooling 7 ¦ Using TypeScript and JavaScript in the same project PART 2 APPLYING TYPESCRIPT IN A BLOCKCHAIN APP 8 ¦ Developing your own blockchain app 9 ¦ Developing a browser-based blockchain node 10 ¦ Client-server communications using Node.js, TypeScript, and WebSockets 11 ¦ Developing Angular apps with TypeScript 12 ¦ Developing the blockchain client in Angular 13 ¦ Developing React.js apps with TypeScript 14 ¦ Developing a blockchain client in React.js 15 ¦ Developing Vue.js apps with TypeScript 16 ¦ Developing the blockchain client in Vue.js

Download or read book Programming TypeScript written by Boris Cherny and published by O'Reilly Media. This book was released on 2019-04-25 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Any programmer working with a dynamically typed language will tell you how hard it is to scale to more lines of code and more engineers. That’s why Facebook, Google, and Microsoft invented gradual static type layers for their dynamically typed JavaScript and Python code. This practical book shows you how one such type layer, TypeScript, is unique among them: it makes programming fun with its powerful static type system. If you’re a programmer with intermediate JavaScript experience, author Boris Cherny will teach you how to master the TypeScript language. You’ll understand how TypeScript can help you eliminate bugs in your code and enable you to scale your code across more engineers than you could before. In this book, you’ll: Start with the basics: Learn about TypeScript’s different types and type operators, including what they’re for and how they’re used Explore advanced topics: Understand TypeScript’s sophisticated type system, including how to safely handle errors and build asynchronous programs Dive in hands-on: Use TypeScript with your favorite frontend and backend frameworks, migrate your existing JavaScript project to TypeScript, and run your TypeScript application in production

Download or read book Learning TypeScript Fundamentals written by Bartlomiej Potaczek and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "TypeScript's popularity seems to only increase since it's being adopted by popular frameworks such as Angular. Optional typing seems like a feature coming to your favorite dynamically typed language soon too. Not only is it a good time to learn JavaScript, but it's also a good time to get acquainted with TypeScript too. This step-by-step guide will get you started with TypeScript with the help of practical examples. You'll start off by installing TypeScript and its compiler, then you'll get familiar with the TypeScript architecture, where we'll look at design goals and language components. Following this, you'll explore the runtime. Next, you'll be introduced to functional programming with TypeScript and will dive into asynchronous programming principles. Moving on, you'll get to know about various functions, its declarations, expressions, and more. We'll explore callbacks and arrow functions, then you'll create higher-order functions and at the end, you will explore promises and generators. After this, we'll explain object-oriented features in detail, where you'll dive into classes. Following this, you'll explore interfaces and generics which make the code reusable. You'll learn to organize the code using Namespaces and you'll understand modules. By the end of this course, you will have learned enough to implement all the concepts with the latest features of TypeScript to build to-do applications from scratch."--Resource description page.

Download or read book TypeScript Essentials written by Christopher Nance and published by Packt Publishing Ltd. This book was released on 2014-10-21 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book introduces the TypeScript language and its features to anyone looking to develop rich web applications. Whether you are new to web development or are an experienced engineer with strong JavaScript skills, this book will get you writing code quickly. A basic understanding of JavaScript and its language features are necessary for this book.

Download or read book Learning TypeScript written by Josh Goldberg and published by "O'Reilly Media, Inc.". This book was released on 2022-06-03 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: TypeScript has conquered the world of JavaScript. Identified in developer surveys as one of the world's fastest growing and most popular languages, TypeScript is widely used in consumer and business companies across the world and is frequently credited for helping massive web applications scale. But what exactly is TypeScript? How and why does it work, and how can we use it? This practical book takes beginner and advanced JavaScript programmers alike from knowing nothing about "types" or "type systems" to full mastery of TypeScript fundamentals. You'll learn: Benefits of TypeScript and general characteristics of its type system Why and how TypeScript is useful on top of "vanilla" JavaScript How to inform your type system by using development-only type annotations How TypeScript analyzes and understands code to help you augment your existing development patterns How TypeScript helps you work with arrays, classes, functions, objects, and other important built-in JavaScript constructs How to effectively use the plethora of TypeScript configuration options to tailor the TypeScript compiler to your teams and projects A variety of IDE integrations such as automated refactors and intelligent code searches provided by TypeScript to help you develop quickly with fewer bugs

Download or read book Learning Typescript written by Remo H. Jansen and published by . This book was released on 2015-09-29 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploit the features of TypeScript to develop and maintain captivating web applications with easeAbout This Book- Learn how to develop modular, scalable, maintainable, and adaptable web applications by taking advantage of TypeScript- Create object-oriented JavaScript that adheres to the solid principles efficiently- A comprehensive guide that explains the fundamentals of TypeScript with the help of practical examplesWho This Book Is ForIf you are a JavaScript developer aiming to learn TypeScript to build beautiful web applications, then this book is for you. No prior knowledge of TypeScript is required.What You Will Learn- Learn the key TypeScript language features and language runtime- Develop modular, scalable, maintainable, and adaptable web applications- Create object-oriented code that adheres to the solid principles- Save time using automation tools like Gulp and Karma- Develop robust applications with testing (Mocha, Chai and SinonJS)- Put your TypeScript skills in practice by developing a single-page web application framework from scratch- Use the JavaScript of tomorrow (ES6 and ES7) today with TypeScriptIn DetailTypeScript is an open source and cross-platform typed superset of JavaScript that compiles to plain JavaScript that runs in any browser or any host. It allows developers to use the future versions of JavaScript (ECMAScript 6 and 7) today. TypeScript adds optional static types, classes, and modules to JavaScript, to enable great tooling and better structuring of large JavaScript applications.This book is a step-by-step guide that will get you started with TypeScript with the help of practical examples. You start off by understanding the basics of TypeScript. Next, automation tools like Grunt are explained followed by a detailed description of function, generics, callbacks and promises. After this, object-oriented features and the memory management functionality of TypeScript are explained. At the end of this book, you will have learned enough to implement all the concepts and build a single page application from scratch.Style and approachThis is a step-by-step guide that covers the fundamentals of TypeScript with practical examples. Each chapter introduces a set of TypeScript language features and leads the readers toward the development of a real-world application.

Download or read book Effective TypeScript written by Dan Vanderkam and published by O'Reilly Media. This book was released on 2019-10-17 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: TypeScript is a typed superset of JavaScript with the potential to solve many of the headaches for which JavaScript is famous. But TypeScript has a learning curve of its own, and understanding how to use it effectively can take time. This book guides you through 62 specific ways to improve your use of TypeScript. Author Dan Vanderkam, a principal software engineer at Sidewalk Labs, shows you how to apply these ideas, following the format popularized by Effective C++ and Effective Java (both from Addison-Wesley). You’ll advance from a beginning or intermediate user familiar with the basics to an advanced user who knows how to use the language well. Effective TypeScript is divided into eight chapters: Getting to Know TypeScript TypeScript’s Type System Type Inference Type Design Working with any Types Declarations and @types Writing and Running Your Code Migrating to TypeScript

Download or read book The TypeScript Workshop written by Ben Grynhaus and published by Packt Publishing Ltd. This book was released on 2021-07-29 with total page 715 pages. Available in PDF, EPUB and Kindle. Book excerpt: Broaden your skill set by learning TypeScript and applying your knowledge to build real-world applications Key FeaturesQuickly get started writing TypeScript code with hands-on exercises and activitiesDevelop new skills that can be applied at work or in your own side projectsBuild your understanding, boost your confidence, and advance your programming careerBook Description By learning TypeScript, you can start writing cleaner, more readable code that's easier to understand and less likely to contain bugs. What's not to like? It's certainly an appealing prospect, but learning a new language can be challenging, and it's not always easy to know where to begin. This book is the perfect place to start. It provides the ideal platform for JavaScript programmers to practice writing eloquent, productive TypeScript code. Unlike many theory-heavy books, The TypeScript Workshop balances clear explanations with opportunities for hands-on practice. You'll quickly be up and running building functional websites, without having to wade through pages and pages of history and dull, dry fluff. Guided exercises clearly demonstrate how key concepts are used in the real world, and each chapter is rounded off with an activity that challenges you to apply your new knowledge in the context of a realistic scenario. Whether you're a hobbyist eager to get cracking on your next project, or a professional developer looking to unlock your next promotion, pick up a copy and make a start! Whatever your motivation, by the end of this book, you'll have the confidence and understanding to make it happen with TypeScript. What you will learnConfigure a professional TypeScript development environmentExplore how to use primitive and complex data typesIncorporate types into popular npm (Node package manager) librariesDesign systems that use asynchronous behaviorImplement object-oriented programming to model real-world scenariosGet to grips with modern UI design by combining React with TypeScriptWho this book is for The TypeScript Workshop is for software developers who want to broaden their skill set by learning the TypeScript programming language. To get the most from this TypeScript book, you should have basic knowledge of JavaScript or experience using another similar programming language.

Download or read book Learning TypeScript 2 x written by Remo H. Jansen and published by Packt Publishing Ltd. This book was released on 2018-04-30 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploit the features of TypeScript to easily create your very own web applications Key Features Develop modular, scalable, maintainable, and adaptable web applications by taking advantage of TypeScript Walk through the fundamentals of TypeScript with the help of practical examples Enhance your web development skills using TypeScript 2.x Book Description TypeScript is an open source and cross-platform statically typed superset of JavaScript that compiles to plain JavaScript and runs in any browser or host. This book is a step-by-step guide that will take you through the use and benefits of TypeScript with the help of practical examples. You will start off by understanding the basics as well as the new features of TypeScript 2.x. Then, you will learn how to work with functions and asynchronous programming APIs. You will continue by learning how to resolve runtime issues and how to implement TypeScript applications using the Object-oriented programming (OOP) and functional programming (FP) paradigms. Later, you will automate your development workflow with the help of tools such as Webpack. Towards the end of this book, you will delve into some real-world scenarios by implementing some full-stack TypeScript applications with Node.js, React and Angular as well as how to optimize and test them. Finally, you will be introduced to the internal APIs of the TypeScript compiler, and you will learn how to create custom code analysis tools. What you will learn Understand TypeScript in depth, including its runtime and advanced type system features Master the core principles of the object-oriented programming and functional programming paradigms with TypeScript Save time using automation tools such as Gulp, Webpack, ts-node, and npm scripts Develop robust, modular, scalable, maintainable, and adaptable applications with testing frameworks such as Mocha, Chai, and Sinon.JS Put your TypeScript skills to practice by developing full-stack web applications with Node.js, React and Angular Use the APIs of the TypeScript compiler to build custom code analysis tool Who this book is for If you are a developer aiming to learn TypeScript to build attractive web applications, this book is for you. No prior knowledge of TypeScript is required. However, a basic understanding of JavaScript would be an added advantage.

Download or read book Learning TypeScript written by Josh Goldberg and published by O'Reilly Media. This book was released on 2022-09-30 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: TypeScript has conquered the world of JavaScript: it's one of the world's fastest growing and most popular languages across developer surveys, widely used in consumer and business companies alike, and frequently credited for helping massive web applications scale. But what is TypeScript? How does it work, why does it work, and how can we use it? Learning TypeScript takes beginner to intermediate JavaScript programmers from knowing nothing about "types" or a "type system" to full mastery of the fundamentals of TypeScript. It's more than a means to find bugs and typos--it's a useful system for declaring the way our JavaScript should work and helping us stick to it. You'll learn how TypeScript: interacts with JavaScript analyzes and understands code augments your existing development pattern helps you document your code works with IDEs to provide refactoring tools assists local development in refactoring code helps you develop more quickly with fewer bugs

Download or read book Essential TypeScript written by Adam Freeman and published by Apress. This book was released on 2019-08-14 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work with Typescript and get the most from this versatile open source language. Author Adam Freeman begins this book by describing Typescript and the benefits it offers, and goes on to show you how to use TypeScript in realistic scenarios, going in-depth to give you the knowledge you need. Starting from the nuts-and-bolts and building up to the most advanced and sophisticated features, you will learn how TypeScript builds on the JavaScript type system to create a safer and more productive development experience and understand how TypeScript can be used to create applications using popular frameworks, including Node.js, Angular, React, and Vue.js. Each topic is covered clearly and concisely and is packed with the details you need to learn to be truly effective. The most important features are given a no-nonsense in-depth treatment and chapters include common problems and details of how to avoid them. What You Will LearnGain a solid understanding of the TypeScript language and toolsUse TypeScript for client- and server-side developmentExtend and customize TypeScriptDebug and unit test your TypeScript code Who This Book Is For Developers who want to start using TypeScript, for example to create rich web applications using Angular, React, or Vue.js Adam Freeman is an experienced IT professional who has held senior positions in a range of companies, most recently serving as chief technology officer and chief operating officer of a global bank. Now retired, he spends his time writing and long-distance running.

Download or read book A Smarter Way to Learn JavaScript written by Mark Myers and published by Createspace Independent Publishing Platform. This book was released on 2017-07-17 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: JavaScript was written to give readers an accurate, concise examination of JavaScript objects and their supporting nuances, such as complex values, primitive values, scope, inheritance, the head object, and more. If you're an intermediate JavaScript developer and want to solidify your understanding of the language, or if you've only used JavaScript beneath the mantle of libraries such as jQuery or Prototype, this is the book for you. This updated and expanded second edition of Book provides a user-friendly introduction to the subject, Taking a clear structural framework, it guides the reader through the subject's core elements. A flowing writing style combines with the use of illustrations and diagrams throughout the text to ensure the reader understands even the most complex of concepts. This succinct and enlightening overview is a required reading for all those interested in the subject . We hope you find this book useful in shaping your future career & Business.

Download or read book Eloquent JavaScript 3rd Edition written by Marijn Haverbeke and published by No Starch Press. This book was released on 2018-12-04 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: Completely revised and updated, this best-selling introduction to programming in JavaScript focuses on writing real applications. JavaScript lies at the heart of almost every modern web application, from social apps like Twitter to browser-based game frameworks like Phaser and Babylon. Though simple for beginners to pick up and play with, JavaScript is a flexible, complex language that you can use to build full-scale applications. This much anticipated and thoroughly revised third edition of Eloquent JavaScript dives deep into the JavaScript language to show you how to write beautiful, effective code. It has been updated to reflect the current state of Java¬Script and web browsers and includes brand-new material on features like class notation, arrow functions, iterators, async functions, template strings, and block scope. A host of new exercises have also been added to test your skills and keep you on track. As with previous editions, Haverbeke continues to teach through extensive examples and immerses you in code from the start, while exercises and full-chapter projects give you hands-on experience with writing your own programs. You start by learning the basic structure of the JavaScript language as well as control structures, functions, and data structures to help you write basic programs. Then you'll learn about error handling and bug fixing, modularity, and asynchronous programming before moving on to web browsers and how JavaScript is used to program them. As you build projects such as an artificial life simulation, a simple programming language, and a paint program, you'll learn how to: - Understand the essential elements of programming, including syntax, control, and data - Organize and clarify your code with object-oriented and functional programming techniques - Script the browser and make basic web applications - Use the DOM effectively to interact with browsers - Harness Node.js to build servers and utilities Isn't it time you became fluent in the language of the Web? * All source code is available online in an inter¬active sandbox, where you can edit the code, run it, and see its output instantly.

Download or read book Learning TypeScript 5 written by Anna Richter and published by GitforGits. This book was released on 2024-04-15 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Programmers familiar with JavaScript who wish to learn more about TypeScript version 5.0 will find this book to be a resource of great value This book is ideal for developers who want to improve their front-end programming skills and integrate TypeScript with popular frameworks such as Angular and React. With clear explanations and hands-on examples, this book makes the transition from JavaScript to TypeScript easy and enjoyable. The book covers fundamental concepts such as static typing, type checking, and type inference, which will help you write more reliable and maintainable code. You'll learn how to use TypeScript's features to improve your development process, reduce bugs, and increase code quality. You'll learn about TypeScript's advanced features, such as interfaces, modules, and type narrowing techniques, through hands-on examples. To help you write more efficient and clean code, this book also covers how to use async/await and Promises to deal with asynchronous operations. "Learning TypeScript 5" offers solutions and troubleshooting techniques for the most common TypeScript challenges that developers face. You'll find out how to make your own error classes for different situations and how to use TypeScript's try/catch blocks to manage errors effectively. Integrating TypeScript with existing JavaScript applications, configuring the TypeScript compiler, and setting up TypeScript projects are all covered in the book. After finishing this book, you will have the knowledge and abilities to create scalable applications with TypeScript and work with frameworks such as Angular and React with ease. Whether you're starting a new project or upgrading an existing one, "Learning TypeScript 5" provides useful insights and practical knowledge to help you improve your development skills and take your programming to the next level. Key Learnings Use TypeScript with Angular and React to create scalable, reliable web apps. Create flawless code with TypeScript's type narrowing and control flow analysis. Maximize productivity in development and application speed by integrating TypeScript with Angular and React. Write cleaner, and more readable scripts with Promises and async/await. Use try/catch and other error handling methods to implement a robust system for managing errors. Master TypeScript's union types, interfaces, and modules for code organization. Maximize code quality with TypeScript's robust testing strategies and robust type-checking capabilities. Table of Content Introduction to TypeScript Working with Basic Types Functions in TypeScript Complex Types and Union Types Classes and Interfaces Modules and Namespaces TypeScript in Practice Runtime Behavior and Type Checking

Download or read book Hands On Functional Programming with TypeScript written by Remo H. Jansen and published by Packt Publishing Ltd. This book was released on 2019-01-30 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover the power of functional programming, lazy evaluation, monads, concurrency, and immutability to create succinct and expressive implementations Key FeaturesGet a solid understanding of how to apply functional programming concepts in TypeScriptExplore TypeScript runtime features such as event loop, closures, and PrototypesGain deeper knowledge on the pros and cons of TypeScriptBook Description Functional programming is a powerful programming paradigm that can help you to write better code. However, learning functional programming can be complicated, and the existing literature is often too complex for beginners. This book is an approachable introduction to functional programming and reactive programming with TypeScript for readers without previous experience in functional programming with JavaScript, TypeScript , or any other programming language. The book will help you understand the pros, cons, and core principles of functional programming in TypeScript. It will explain higher order functions, referential transparency, functional composition, and monads with the help of effective code examples. Using TypeScript as a functional programming language, you’ll also be able to brush up on your knowledge of applying functional programming techniques, including currying, laziness, and immutability, to real-world scenarios. By the end of this book, you will be confident when it comes to using core functional and reactive programming techniques to help you build effective applications with TypeScript. What you will learnUnderstand the pros and cons of functional programming Delve into the principles, patterns, and best practices of functional and reactive programming Use lazy evaluation to improve the performance of applicationsExplore functional optics with Ramda Gain insights into category theory functional data structures such as Functors and Monads Use functions as values, so that they can be passed as arguments to other functionsWho this book is for This book is designed for readers with no prior experience of functional programming with JavaScript, TypeScript or any other programming language. Some familiarity with TypeScript and web development is a must to grasp the concepts in the book easily.

Download or read book Learn TypeScript written by Yasin Hasan Cakal and published by Independently Published. This book was released on 2023-01-21 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Welcome to "Learn Typescript," the ultimate book for learning the popular programming language. Typescript is a supercharged version of JavaScript that provides optional static typing, class-based object-oriented programming, and other advanced features. In this book, you will learn everything you need to know to get started with Typescript and start using it in your projects. Throughout this book, you will learn the fundamentals of Typescript, including its syntax, types, variables, interfaces, classes, functions, and more. You will also learn how to use advanced Typescript features like enums, decorators, namespaces, and modules. This book is designed for both beginners and experienced programmers who want to learn Typescript and take their skills to the next level. Whether you are a web developer, mobile developer, or just looking to expand your programming skills, this book has something for you. So if you're ready to learn the power of Typescript and start using it in your projects, join us in "Learn Typescript" today and take your programming skills to the next level!

Download or read book JavaScript Allong written by Reginald Braithwaite and published by Justin Kelly. This book was released on 2013-10-04 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: JavaScript Allongé solves two important problems for the ambitious JavaScript programmer. First, JavaScript Allongé gives you the tools to deal with JavaScript bugs, hitches, edge cases, and other potential pitfalls. There are plenty of good directions for how to write JavaScript programs. If you follow them without alteration or deviation, you will be satisfied. Unfortunately, software is a complex thing, full of interactions and side-effects. Two perfectly reasonable pieces of advice when taken separately may conflict with each other when taken together. An approach may seem sound at the outset of a project, but need to be revised when new requirements are discovered. When you “leave the path” of the directions, you discover their limitations. In order to solve the problems that occur at the edges, in order to adapt and deal with changes, in order to refactor and rewrite as needed, you need to understand the underlying principles of the JavaScript programming language in detail. You need to understand why the directions work so that you can understand how to modify them to work properly at or beyond their original limitations. That’s where JavaScript Allongé comes in. JavaScript Allongé is a book about programming with functions, because JavaScript is a programming language built on flexible and powerful functions. JavaScript Allongé begins at the beginning, with values and expressions, and builds from there to discuss types, identity, functions, closures, scopes, and many more subjects up to working with classes and instances. In each case, JavaScript Allongé takes care to explain exactly how things work so that when you encounter a problem, you’ll know exactly what is happening and how to fix it. Second, JavaScript Allongé provides recipes for using functions to write software that is simpler, cleaner, and less complicated than alternative approaches that are object-centric or code-centric. JavaScript idioms like function combinators and decorators leverage JavaScript’s power to make code easier to read, modify, debug and refactor, thus avoiding problems before they happen. JavaScript Allongé teaches you how to handle complex code, and it also teaches you how to simplify code without dumbing it down. As a result, JavaScript Allongé is a rich read releasing many of JavaScript’s subtleties, much like the Café Allongé beloved by coffee enthusiasts everywhere. License: CC BY-SA 3.0 Source is available from Github * https://github.com/justinkelly/javascript-allonge