JavaScript and Open Data

This book will teach you how to take advantage of the JavaScript language to process data provided on the Internet. Much attention is given to the main JavaScript backbone: prototype based objects, and functional capabilities, while common features (loops, etc.) are summarized in a few cheat-sheets. Only operational features are detailed through the coding of several applications -the second and largest part of the book-, on free-access datasets (e.g. World Bank). It includes: cartography (SVG or API's based), data-sheets access (via Ajax or Jsonp), video data and post-synchronization, and animation examples.

Introduction xiii Part 1. Core JavaScript 1 Introduction to Part 1 3 Chapter 1. Variables: Declaration, Definition and Type 5 1.1. Declarations of functions and variables 6 1.1.1. The different declaration keywords 6 1.1.2. Lexical scope and definition of a variable according to declaration mode: var, let, const 9 1.1.3. Comments (important improvements carried over by ES6) 11 1.1.4. General conclusion about the variable declarations in JavaScript 11 1.1.5. Naming variables and functions: best practices 14 1.2. Variable definition, initialization and typing in JavaScript 15 1.2.1. Variables initialization and definition 15 1.2.2. Types 15 1.2.3. How to use the type “undefined” and the value undefined 17 Chapter 2. Controls: Booleans, Branch and Loops 19 2.1. Truth values and boolean operators 19 2.1.1. Boolean operators: “!” (not), “&&” (and), “||” (or) 19 2.1.2. Relational operators: >, =,