A

a (HTML tag), HTML, Attributes, Styling, Focus

Abelson, Hal, Project: A Programming Language

absolute path, Content Negotiation, Again

absolute positioning, Query Selectors, Elements by Tag Name, Key Events, Scroll Events, Summary

abstract syntax tree, Parsing (see syntax tree)

abstraction, Higher-Order Functions, Abstracting Array Traversal, Higher-Order Functions, Composability, Project: A Programming Language, Networks and the Internet, The Standard

acceleration, Actors and Actions

Accept header, Summary, Error Handling, The Pie Chart

access control, Animating Life, The Locked Box, Using Functions as Namespaces, HTTP Interface

Access-Control-Allow-Origin header, Fetching XML Data

actionTypes object, More Life-forms

activeElement property, Fields

actor, Reading a Level, Drawing, Motion and Collision, Back to the Game

actorAt method, Motion and Collision

addEntry function, Mutability

addEventListener method, Event Handlers, Actors and Actions, Streams

addition, Numbers, A Vector Type

address, HTTP

address bar, The Web, HTTP, The Protocol

adoption, Regular Expressions

age difference (exercise), Binding, Deep Comparison

alert function, Functions, The Call Stack, HTML

algorithm, Color Picker

algorithmic optimization, Going Back to Old-school Loops, Optimizing

alignment, Getters and Setters

all function, Waiting for Multiple Promises, Waiting for Multiple Promises

alpha, Color Picker

alphanumeric character, Matching a Set of Characters

alt attribute, Changing the Document

ALT key, Key Events

altKey property, Key Events

ambiguity, Arrays

AMD, Slow-Loading Modules, Slow-Loading Modules

American English, Repeating Parts of a Pattern

ampersand character, HTML, The Protocol

analysis, Bugs and Error Handling, Debugging

ancestor element, Drawing

ancestry example, JSON, The Cost

ANCESTRY_FILE data set, JSON

angle, Positioning and Animating, Curves, Finishing Up, Pausing the Game

angle brackets, HTML

animate method, Motion and Collision

animation, It Moves, Populating the New World, Positioning and Animating, Positioning and Animating, Positioning and Animating, Elements by Tag Name, Mouse Motion, Summary, Drawing, Motion and Collision, Motion and Collision, Running the Game, Running the Game, Images, Storing and Clearing Transformations, Back to the Game, Choosing a Graphics Interface

avoiding stutter, Positioning and Animating

cat in ellipse, Positioning and Animating

collision detection, Motion and Collision

frames for, Images, Storing and Clearing Transformations

game, Drawing, Motion and Collision, Running the Game

getting elements by tag name, Elements by Tag Name

mouse trail, Summary

off-screen, Mouse Motion

scheduling, Positioning and Animating

simple, It Moves, Populating the New World

sprite, Back to the Game

stopping, Running the Game

SVG vs. canvas, Choosing a Graphics Interface

anonymous function, Using Functions as Namespaces

appendChild method, Finding Elements, Drawing, Closure

Apple, In the Sandbox

application (of functions), Defining a Function (see function application)

apply method, Higher-Order Functions, Methods

approximation, Project: Electronic Life

arc, Curves

arc method, Curves, The Pie Chart

arcTo method, Curves, Curves

area, Finishing Up

argument, Functions, The Call Stack, Recursion, Backtracking, Parsing

arguments object, Strings and Their Properties, Higher-Order Functions, Recursion

argv property, The node Command

arithmetic, Numbers, Logical Operators, The Environment

Armstrong, Joe, The Secret Life of Objects

array, The Weresquirrel, Data Sets, Properties, Objects, The Lycanthrope’s Log, Computing Correlation, The Final Analysis, The Final Analysis, Further Arrayology, The Sum of a Range, The Sum of a Range, Abstracting Array Traversal, Abstracting Array Traversal, JSON, JSON, Transforming with map, Composability, Binding, Mother-Child Age Difference, Mother-Child Age Difference, Definition, Representing Space, Representing Space, A Critter’s Programming Interface, Arrays, Color Picker, Long-Polling Support, Recursion, Recursion, Elements by Tag Name

as grid, Definition, Color Picker

as table, The Lycanthrope’s Log

creation, The Weresquirrel, Composability, Representing Space, Recursion

defined, Objects

Egg support, Arrays

every method, Mother-Child Age Difference

filtering, JSON

flattening, Binding

forEach method, Abstracting Array Traversal

higher-order functions and, JSON

indexing, Data Sets, Recursion, Elements by Tag Name

length property, Properties, Representing Space

map method, Transforming with map

methods, The Final Analysis

objects and, The Sum of a Range

random element from, A Critter’s Programming Interface

reverse method, The Sum of a Range

searching, Computing Correlation, The Final Analysis

slice method, Further Arrayology

some method, Mother-Child Age Difference

splice method, Long-Polling Support

traversal, Abstracting Array Traversal

Array constructor, Representing Space

Array prototype, Prototypes, Constructors

array-like object, Higher-Order Functions, Predictability, Focus, File Fields, Installing with NPM

arrow function, this and Its Scope

artificial intelligence, Project: Electronic Life, More Life-forms, Bringing the World to Life, Compilation, A Vector Type

artificial life, Project: Electronic Life, The Game, Autocompletion

artificial stupidity (exercise), Bringing the World to Life, A Vector Type

ASCII art, Installing with NPM

assert function, Selective Catching

assertion, Selective Catching, Assertions

assignment, Variables, Breaking Out of a Loop, The lastIndex Property, Parsing an INI File, Arrays, Closure

assumption, Selective Catching, Assertions

asterisk, Numbers, Repeating Parts of a Pattern

asynchronous I/O, Slow-Loading Modules, Sending a Request, Background

asynchronous programming, Slow-Loading Modules, Slow-Loading Modules, Running the Game, Sending a Request, Abstracting Requests, Abstracting Requests, Promises, File Fields, Background, Background, Asynchronicity, Asynchronicity, Installing with NPM, Streams

callbacks, Sending a Request, Abstracting Requests

code execution path and, Slow-Loading Modules

defined, Running the Game

dependencies and, Slow-Loading Modules

error handling, Abstracting Requests

functions and, Installing with NPM

Node and, Background

overview, Background, Asynchronicity

parallelism and, Asynchronicity

promise interface, Promises

reading files, File Fields

writable streams, Streams

attack, Fetching XML Data

attribute, HTML, Creating Nodes, Project: A Paint Program, Waiting for Multiple Promises, Autocompletion

Aurelius, Marcus, Handling Events

authorization, HTTP Interface

autocompletion (exercise), Autocompletion, Waiting for Multiple Promises

autofocus attribute, Fields

automatic semicolon insertion, Expressions and Statements

avatar, The Game

average function, Summarizing with reduce, Binding, Mother-Child Age Difference, Deep Comparison

axis, Actors and Actions, The Canvas Element, Transformation