Chapter 1, Getting Started with Underscore.js, introduces you to Underscore and explains the main problems addressed by the library together with a quick introduction to functional programming. This chapter describes some of the concepts and patterns that are used by Underscore or are helpful when using Underscore. The final part is a walkthrough to set up the development environment used throughout the book with a starter example.

Chapter 2, Using Underscore.js with Collections, explores the Underscore functionality for collections by example and explains some of the concepts related to these areas—scope resolution and execution context, map/reduce, and functional programming concepts.

Chapter 3, Using Underscore.js with Arrays, Objects, and Functions, looks at functionality for arrays, objects, and functions and builds upon the concepts and functions introduced in the previous chapter. In the functions section, you will learn how to manipulate function scopes and arguments and why this is an important aspect of JavaScript programming in general.

Chapter 4, Programming Paradigms with Underscore.js, expands on the concepts and practices of functional programming to solve common programming problems. The chapter starts with a differentiation between object-oriented programming and functional programming. It continues by exploring examples of functional programming with Underscore.

Chapter 5, Using Underscore.js in the Browser, on the Server, and with the Database, is about using Underscore in specific contexts, starting with the browser environment, closely followed by Node.js server-side applications or libraries. You will then learn how to use Underscore with databases such as MongoDB and PostgreSQL, which can execute JavaScript to query data.

Chapter 6, Related Underscore.js Libraries and ECMAScript Standards, discusses advanced topics such as the link between Underscore and JavaScript standards, libraries that augment or can even replace Underscore, with a focus on taking advantage of the new ECMAScript 2015 (ES6) features.

Chapter 7, Underscore.js Build Automation and Code Reusability, introduces a build automation solution together with strategies to reuse Underscore based code between different application hosts.

You need to have the Node.js runtime installed and it is available at https://nodejs.org/. Details on how to install it can be found in Chapter 1, Getting Started with Underscore.js.

All the code in this book can be edited in any text editor or IDE that you are familiar with and has support for the JavaScript language.

This book is for developers with fundamental JavaScript knowledge who want to use modern JavaScript libraries to advance their programming skills. Underscore is one of the most important libraries you should be familiar with and the book will help you achieve this goal by going through its fundamentals and using it in a wide variety of contexts. This book should be relevant to anyone who:

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "We just need to open the SpecRunner.html file in a browser and we should see this output."

A block of code is set as follows:

var peopleWithAwardAge = _.map(people, function(person){
  return {
    name: person.name,
    awardAge: person.awardYear - person.birthYear
  }
});

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

var peopleWithAwardAge = _.map(people, function(person){
  return {
    name: person.name,
    awardAge: person.awardYear - person.birthYear
  }
});

Any command-line input or output is written as follows:

npm install -g bower

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Executing the following line in a Command Prompt with administrator privileges (opened using the Run as administrator option)."

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To send us general feedback, simply e-mail <[email protected]>, and mention the book's title in the subject of your message.

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Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.