INDEX

Symbols and Numbers

&& operator, 17, 20, 95

* operator, 13, 18–19, 148

*= operator, 34

{} (block), 29

{} (object), 63, 66

- operator, 13, 16, 18–19

-- operator, 34

-= operator, 34

= operator, 24–25, 63, 348

for default value, 48

in Egg, 209–210

as expression, 160, 162

== operator, 17, 19, 66, 80, 193

=== operator, 19, 80, 113, 410

! operator, 17, 31

!= operator, 17

!== operator, 19

/ operator, 13, 396

/= operator, 34

> operator, 16

>= operator, 17

< operator, 16

<= operator, 17

% operator, 14, 33, 297, 407, 408, 418, 420

+ operator, 13, 15, 19, 148, 404

++ operator, 34

+= operator, 34, 199

?: operator, 18, 20, 209

[] (array), 60

[] (subscript), 60, 61

|| operator, 17, 20, 51, 95, 328, 408

2d (canvas context), 289

200 (HTTP status code), 312, 360, 364

204 (HTTP status code), 366, 367

304 (HTTP status code), 374, 380, 386

400 (HTTP status code), 425

403 (HTTP status code), 364

404 (HTTP status code), 312, 365, 377–379

405 (HTTP status code), 316, 364

406 (HTTP status code), 422

500 (HTTP status code), 364

A

a (HTML tag), 222, 235, 237, 320, 344

Abelson, Hal, 202

absolute positioning, 240, 244, 253, 257, 262

absolute value, 76, 424

abstract data type, 96

abstract syntax tree, see syntax tree

abstraction, 5, 41, 84, 86, 203, 316, 349

in Egg, 230

of the network, 221

acceleration, 281–282

Accept header, 329, 422

access control, 98, 141–142, 375

Access-Control-Allow-Origin header, 316

actions, 334, 336, 337

activeElement property, 319

actor, 269, 274, 280

add method, 113

addEntry function, 66

addEventListener method, 248, 282, 362

addition, 13, 113

address, 77, 311

address bar, 221, 311, 313

adoption, of tools and techniques, 145

ages example, 104

alert function, 223–224

algorithmic optimization, 397, 406

alpha, 346

alphanumeric character, 147

alt attribute, 233

ALT key, 252

altKey property, 252

ambiguity, 215

American English, 148

ampersand character, 223, 314

analysis, 129, 133

ancestor element, 275

Android, 252

angle, 242, 293, 294, 421

angle brackets, 222

animation, 256, 262, 271, 306, 419

bouncing ball, 308, 421

performance, 266

platform game 277, 283, 296, 297, 303, 305

spinning cat, 240, 241, 244

anyStorage function, 198–199, 200

appendChild method, 232, 417

Apple, 225

application (of functions), see function

application applications, 1, 333, 372

arc, 293, 294

arc method, 293, 421

argument, 27, 47, 51, 74, 155, 204

arguments object, 409

argv property, 355

arithmetic, 13, 19, 210

array, 61, 64, 79, 95

counting, 93

creation, 91, 60, 336, 409, 413

in Egg, 214

filtering, 88

indexing, 60, 68, 72, 409, 418

iteration, 69, 85, 87

length of, 61

as matrix, 107–108, 268

methods, 71, 79, 87–89, 92, 94, 95

notation, 77

random element, 122

as regular expression match, 149

representation, 77

of rest arguments, 74

searching, 68, 71

as table, 67

Array constructor, 336

Array prototype, 100, 103

Array.from function, 195, 231, 356

array-like object, 230–232, 255, 320, 325, 358

arrays in Egg (exercise), 214, 416

arrow function, 45, 99, 199

arrow keys, 262

artificial intelligence, 117, 213

assert function, 140

assertion, 140

assignment, 25, 34, 160, 162, 215, 417

assumption, 139, 140

asterisk, 13, 148

async function, 195–196, 199, 200, 386

asynchronous programming, 181, 200

animation, 284

in Node.js, 354, 359, 361, 365, 368

reading files, 325

attribute, 222, 230, 235, 320, 337, 422

autofocus attribute, 320

automatic semicolon insertion, 24

automation, 125, 132

automaton, 117

avatar, 266

average function, 91

await keyword, 195–196, 197, 199

axis, 281, 289, 298, 424

B

Babbage, Charles, 58

background, 266, 273, 278

background (CSS), 262, 266, 274

backslash character

as path separator, 365

in regular expressions, 146, 147, 157, 158, 414

in strings, 14, 223

backtick, 14–15

backtracking, 153–154, 156–157

ball, 308, 421

balloon (exercise), 262, 418

banking example, 137

Banks, Iain, 264

baseControls constant, 348

baseTools constant, 348

bean counting (exercise), 56, 409

beforeunload event, 258

behavior, 164, 213

benchmark, 236, 391, 397

Berners-Lee, Tim, 218

best practices, 3

bezierCurveTo method, 292

big ball of mud, 167, 168

binary data, 3, 11, 358

binary numbers, 11, 12, 68, 133, 153, 324

binary operator, 13, 16, 23

binding

assignment, 25, 44

compilation of, 215, 403

definition, 24, 41, 215, 417

destructuring, 76

in Egg, 210, 212

exported, 173

global, 43, 130, 285, 354, 355

local, 43

model of, 25, 63, 65

naming, 26, 35, 52, 75, 131

from parameter, 42, 49

scope of, 43

as state, 31, 33, 65, 160, 326

undefined, 138

visibility, 43

bitfield, 255

bitmap graphics, 295, 308

bits, 3, 11, 12, 16, 68

block, 29, 32, 42, 43, 46, 63, 136, 137, 204

block comment, 36, 156

block element, 235, 237–238

blocking, 182, 241, 260, 359

blur event, 257–258

blur method, 319

body (HTML tag), 222–223, 228

body (HTTP), 313–315, 360, 366, 367, 378

body property, 228, 229, 231, 316

bold, 237 Book of Programming, The, 10, 352

Boolean, 16, 28, 31, 65, 146, 209, 210

conversion to, 19, 28, 31

Boolean function, 28

border (CSS), 235, 237

border-radius (CSS), 253

bouncing, 267, 270, 278, 280, 308

boundary, 151, 153, 157, 161, 164, 302, 413

bounds, of ranges, 88

box, 142, 227, 266, 308, 421

box shadow (CSS), 275

br (HTML tag), 340, 422

braces

block, 4, 29, 42

class, 102

function body, 46, 63, 408

object, 66, 76, 85

in regular expression, 148

branching, 152, 153

branching recursion, 50, 300

break keyword, 33, 35

breakpoint, 134

British English, 148

broadcastConnections function, 193

browser, 2, 5, 174, 183, 219–225, 266, 267, 308, 313, 316, 321, 344, 348, 372

environment, 7, 26, 27, 311

security, 317, 392

storage, 326–328

window, 248

browser wars, 225

bubbling, see event propagation

Buffer class, 358, 359, 361, 362

bug, 83, 129, 133, 157, 159, 164, 168, 225

building Promise.all (exercise), 200, 416

bundlers, 174

button, 247, 313, 320, 330

button (HTML tag), 224, 248, 252, 262, 321, 327, 330, 337

button property, 249, 255, 338

buttons property, 255, 338

C

C (programming language), 391

cache, 172, 184

call method, 99, 104

call protocol, 400

call stack, 46–47, 51, 62, 135, 136, 138, 197, 400

callback functions, 184–190, 247, 283, 337, 358–359, 361, 380, 385

calling (of functions), see function application camel case, 35, 238

cancelAnimationFrame function, 260

canvas, 266, 287, 289–292, 295–301, 305–307, 395, 421

context, 289

path, 290

size, 288, 290

canvas (HTML tag), 288, 334, 337, 344, 345, 349, 423

CanvasDisplay class, 301, 302, 304

capitalization, 35, 101, 149, 238, 243, 362

capture group, 149–151, 155, 376

career, 265

caret character, 147, 151, 161, 358

carriage return, 161

cascading, 238

Cascading Style Sheets, see CSS case conversion, 62

case keyword, 35

case sensitivity, 149, 414

casual computing, 2

cat’s hat (exercise), 244

catch keyword, 135–136, 138–139, 141, 197, 413

catch method, 188

CD, 11

cell, 330

Celsius, 110

centering

image on screen, 241

player in viewport, 276

certificate, 317

change event, 319, 322, 340, 422, 425

character, 14–15, 92–93, 322

character category, 163

character encoding, 358–359

characterCount function, 90

characterScript function, 94, 95, 411

charCodeAt method, 92

checkbox, 318, 323, 330, 422

checked attribute, 318, 323

chessboard (exercise), 38, 408

chicks function, 198–199

child node, 229, 230, 232

childNodes property, 230, 231, 233, 419

children property, 231

Chinese characters, 92, 94

choice, 152

Chrome, 225, 398, 400, 402, 404

circle, 241, 293

circle (SVG tag), 288

circles (exercise), 350, 423

circular dependency, 178, 415

circus, 71

class, 101, 102, 113, 119, 267, 335

class attribute, 232, 235, 239, 273, 275

class declaration, 102

class hierarchy, 112

className property, 235

cleaning up, after exceptions, 136

clearing, the canvas, 288, 296, 301, 302, 421

clearInterval function, 260

clearRect method, 296, 421

clearTimeout function, 259, 260

click event, 248, 250, 253, 255, 337, 422

client, 220, 316, 361, 372, 381, 382

clientHeight property, 235

clientWidth property, 235

clientX property, 253, 255, 339

clientY property, 253, 255, 339

clipboard, 225

clipping, 302

closePath method, 291

closing tag, 222, 224

closure, 49, 214, 417–419

closure in Egg (exercise), 214, 417

code, 6, 156, 265

structure of, 23, 32, 41, 167, 175

code golf, 164

code unit, 92

codePointAt method, 93

coin, 266, 267, 280, 305

Coin class, 271, 280

collaboration, 219

collection, 5, 60, 62, 64, 79

collision detection, 277, 278, 280–282, 420, 421

colon character, 18, 34, 63, 237

color, 288, 290, 302, 334, 346

color (CSS), 237, 238

color codes, 336

color field, 334, 336, 341

color picker, 334, 341, 344

color property, 335

ColorSelect class, 341

comma character, 204

COMMAND key, 252, 349

command line, 169, 353–355, 368

comment, 35, 77, 156, 160, 214, 229, 372, 374, 379, 384, 417

comment field reset (exercise), 388, 426

COMMENT_NODE code, 229

comments in Egg (exercise), 214, 417

CommonJS modules, 171–173, 355–356

exercise, 177–178, 415

communication, 220, 316

community, 354

compareRobots function, 125

comparison, 16, 19, 31, 35, 80

deep, 210, 409

of NaN, 17

of numbers, 16, 27

of objects, 66

of strings, 16

of undefined values, 19

compatibility, 5, 219, 225, 350, 357

compilation, 174, 212, 213, 391, 392, 398, 400, 403, 417

complexity, 3, 83, 112, 154, 239, 272, 349

component, 334, 335, 340, 346

composability, 5, 91, 175

computed property, 61, 328

computers, 1, 2

concat method, 72, 95, 413, 418, 426

concatenation, 15, 72, 418

conditional execution, 18, 28, 34, 37, 209

conditional operator, 18, 20, 209

conditional request, 374

configuration, 160

connected graph, 125

connection, 220, 311, 317, 372, 373

connections binding, 192

consistency, 35, 219, 230

console.log function, 5, 8, 16, 27, 46, 48, 55, 133, 354, 362–363, 398

const keyword, 25–26, 43, 65, 75, 76

constants, 26, 75, 282

constructor, 35, 101, 102, 112, 126, 130, 136, 150, 157, 411, 413

content negotiation (exercise), 329, 422

Content-Length header, 313

Content-Type header, 313, 360, 365, 369

context, 289

context menu, 251

continuation, 184

continue keyword, 33

control, 339, 341, 344, 347

control flow

asynchronous, 182, 196

conditional, 28–30

exceptions, 135, 136

function, 46, 86

loop, 30–31, 32–33

control point, 292, 293

convention, 35

convergent evolution, 184

Conway’s Game of Life, 330

coordinates, 113, 241–242, 253, 273, 276, 278, 279, 289, 293, 298

copy-paste programming, 53, 168

copyright, 169

correlation, 66, 67, 69, 70

corvid, 183

cosine, 75, 241

countBy function, 93, 95

counter variable, 30, 32, 242, 408, 409, 416, 418

CPU, 182

crash, 138, 140, 378, 387

createElement method, 234, 336, 417

createReadStream function, 362, 365

createServer function, 360, 362, 375, 376

createTextNode method, 233, 422

createWriteStream function, 361, 367

cross-domain request, 316

crow, 183, 184, 188, 194

crow-tech module, 185

crying, 149

cryptography, 317

CSS, 237–239, 273–277, 287, 290, 336, 382

CTRL key, 252, 349

ctrlKey property, 252, 349

curl program, 367

curly braces, see braces cursor, 322

curve, 292–293

cutting point, 272

cwd function, 364–365

cycle, 229

D

Dark Blue (game), 265

data, 2, 11, 59

data attribute, 235, 262

data event, 362

data flow, 334, 349

data format, 77, 230

data loss, 387

data set, 68, 87

data structure, 59, 175, 177, 306, 330

collection, 60

immutable, 120

list, 79

map, 104

stack, 62

tree, 204, 227, 229

data URL, 344–345

date, 147, 148, 150

Date class, 150, 151, 169, 171

date-names package, 171

Date.now function, 151, 346, 405

dblclick event, 253

De Morgan’s laws, 411

debouncing, 260

debugger statement, 134

debugging, 6, 129–131, 133, 136, 139, 140, 164

decentralization, 219

decimal number, 11, 133, 153

declaration, 237

decodeURIComponent function, 314, 364, 376

deep comparison, 66, 80

deep comparison (exercise), 80, 410

default behavior, 237, 251

default export, 173

default keyword, 35

default value, 20, 48, 290, 328, 348

defineProperty function, 411

defineRequestType function, 185, 190

degree, 293, 298

delete method, 113

DELETE method, 312–313, 315, 363, 366, 378

delete operator, 63

deoptimization, 401, 403, 404

dependence, 66

dependency, 168, 170, 173, 178, 224, 357

deserialization, 77

design, 168

destructuring, 151

destructuring assignment, 424

destructuring binding, 76, 171, 348, 415

developer tools, 7, 27, 134, 138

dialect, 174

dialog box, 26

diamond, 307, 420

digit, 11, 12, 133, 147–149, 336

Dijkstra, Edsger, 116, 176

Dijkstra’s algorithm, 176

dijkstrajs package, 176, 414

dimensions, 113, 235, 265, 267, 278, 289, 401, 408

dinosaur, 213

direct child node, 239

direction (writing), 95

directory, 355, 358–359, 363, 365–366, 368, 425

directory creation (exercise), 368, 425

disabled attribute, 320

discretization, 266, 278, 283

dispatch, 34, 334–336, 340, 347, 375, 423

display, 272, 273, 283, 284, 301, 305, 306

display (CSS), 237, 262

distance, 396, 423

distribution, 392

division, 13, 14, 396

division by zero, 14

do loop, 31, 122

doctype, 222–223

document, 221, 227, 258, 287

document format, 317, 329

Document Object Model, see DOM

documentation, 353

documentElement property, 228, 229

dollar sign, 26, 151, 155, 161

DOM, 228, 229

attributes, 235

components, 334

construction, 230, 232, 234, 336

events, 248, 252

fields, 318, 322

graphics, 266, 267, 273–276, 287, 288, 305

interface, 229–230

modification, 232–233

querying, 231–232, 239

tree, 229

dom property, 335

domain, 221, 313, 316, 327

domain-specific language, 84, 132, 145, 214, 239

DOMDisplay class, 273, 301

dominant direction (exercise), 95, 411

done property, 346

doneAt property, 346

dot character, see period character

double-click, 253

double-quote character, 14, 165, 204, 223

download, 7, 169, 344, 356, 367, 371, 387

download attribute, 344

draggable bar example, 254

dragging, 254, 334, 342, 350

draw function, 342, 350

drawGraph function, 395

drawImage method, 295–296, 298, 301, 303, 421

drawing, 227, 235, 236, 241, 272, 273, 288, 289, 292, 299, 303, 305, 333, 334, 422

drawing program example, 253, 333

drawPicture function, 338, 344, 350, 423

drop-down menu, 319, 324

duplication, 168

dynamic typing, 403

E

ECMAScript, 5, 6, 173

ECMAScript 6, 6, 426

economic factors, 349

ecstatic package, 376

Edge, 398, 400, 402

editor, 32

efficiency, 50, 79, 91, 192, 212, 236, 266, 275, 289, 338, 349

efficient drawing (exercise), 349, 423

Egg language, 203, 215, 229

electronic life, 266

elegance, 50, 205

element, 222, 229, 231, 234

ELEMENT_NODE code, 229, 418

elements property, 320

ellipse, 240, 242

else keyword, 29

elt function, 234, 336, 349, 384

email, 317

emoji, 15, 92, 162, 262

empty set, 156

encapsulation, 97, 98, 105, 112, 248, 272

encodeURIComponent function, 314, 373–374, 383

encoding, 220

encryption, 317

end event, 362

end method, 360, 361, 364

enemies example, 160

engine, 391, 398, 400, 402

engineering, 225

ENOENT (status code), 365

ENTER key, 321

entity, 223

enum (reserved word), 26

environment, 26, 208

equality, 17

error, 92, 129, 130, 133–135, 138, 139, 187, 188, 194

error event, 326, 367

error handling, 129, 135, 138, 359, 364, 365, 383, 386

error message, 207, 330

error recovery, 134

error response, 312, 364, 366

error tolerance, 223

Error type, 136, 138, 139, 365

ES modules, 173, 224

ESC key, 285

escaping

in HTML, 222, 224

in regular expressions, 146, 147, 158

in strings, 14, 204

in URLs, 314, 364, 373–374, 376

Escher, M.C., 286

ETag header, 374, 380, 386

eval operator, 170

evaluate function, 207–208, 210

evaluation, 170, 207, 213

even numbers, 30, 56

event handling, 247–262, 266, 282, 284, 285, 295–296, 305, 321, 322, 337, 362, 419, 422

event loop, 197

event object, 249, 253, 255

event propagation, 249, 250, 257, 258

event type, 249

every method, 95

everything (exercise), 95, 411

everywhere function, 192

evolution, 145, 349, 357

exception handling, 135, 136, 138–142, 187, 188, 196, 197, 200, 416, 422

exception safety, 138

exec method, 149–150, 158, 160

execution order, 28, 45, 46

exercises, 2, 7, 37, 133

exit method, 354

expectation, 251

experiment, 3, 7, 164

exploit, 225

exponent, 13, 165, 414

exponentiation, 31, 33

export keyword, 173

exports object, 171–173, 356, 415

expression, 23, 24, 27, 31, 33, 44, 203, 204, 208

expressivity, 214

extension, 355

extraction, 150

F

factorial function, 8

Fahrenheit, 110

fallthrough, 35

false, 16

farm example, 52, 54, 152

fetch function, 315, 329, 361, 383, 385, 425

field, 252, 313, 318, 320, 323, 326, 330, 334, 388

Fielding, Roy, 310

file, 168, 325, 426

access, 172, 174, 345, 358, 359

image, 333, 344

resource, 312, 313, 363, 365, 366

stream, 361

file extension, 365

file field, 318, 325

file format, 160

file reading, 325

file server, 381

file server example, 363, 365–369, 425

file size, 174

file system, 325, 358, 359, 363, 364, 425

File type, 325

FileReader class, 325, 326, 345

files property, 325

fill function, 343

fill method, 291, 336

fillColor property, 336

filling, 289–291, 295, 306

fillRect method, 289, 296

fillStyle property, 290, 295

fillText method, 295, 420

filter method, 88, 91, 94, 120, 191, 411, 413

finally keyword, 137, 142, 413

findIndex method, 94

findInStorage function, 194, 195

findRoute function, 124, 193

finish event, 367

Firefox, 225, 398, 400, 402, 404

firewall, 372

firstChild property, 230

fixed positioning, 257

fixing scope (exercise), 215, 417

FizzBuzz (exercise), 37, 407

flattening (exercise), 95

flexibility, 6

flipHorizontally function, 304, 420

flipHorizontally method, 298

flipping, 297–298

floating-point number, 12–13

flood fill, 340, 343

flooding, 192

flow diagram, 152, 153

focus, 252, 257, 319, 320, 322, 323, 349, 388

focus event, 257–258

focus method, 319

fold, see reduce method font, 295

font-family (CSS), 238

font-size (CSS), 262

font-weight (CSS), 238

for attribute, 323

for loop, 32, 33, 69, 85, 95, 139, 397, 409, 410

for/of loop, 69, 93, 106, 107, 109, 398, 412

force, 393–398

force-directed graph layout, 393

forceDirected_noRepeat function, 397

forceDirected_noVector function, 401

forceDirected_simple function, 396

forceDirected_skip function, 398

forEach method, 87

form, 313, 314, 320, 321, 369

form (HTML tag), 318, 320, 385, 425

form property, 320

formatDate module, 171, 173

fractal example, 300

fractional numbers, 13, 165, 266

fragmentation, 402

frame, 296, 297, 303, 421

framework, 54, 334

frequency table, 67

fs package, 358, 359

Fuller, Margaret, 370

function, 5, 26, 41, 45, 130, 203, 204, 211

application, 26, 27, 42, 46, 47, 50, 74, 88, 138, 203, 208

body, 42, 46

callback, see callback function

   declaration, 45

definition, 41, 45, 52

higher-order, 45, 85, 86, 88, 89, 91, 155, 283

inlining, 400

model of, 49

naming, 52–54

as property, 62

purity, 55

scope, 44, 169, 214

as value, 42, 44, 48, 85, 86, 88, 249, 283, 419

Function constructor, 170, 172, 210, 213, 330, 422

function keyword, 42, 45

Function prototype, 100, 103

future, of JavaScript, 6, 26, 45, 308

G

game, 265–267, 282, 284, 285, 301

with canvas, 305

screenshot, 277, 305

game of life (exercise), 330, 422

GAME_LEVELS data set, 284

garbage collection, 12, 400–403

garble example, 355

gardening, 371

gaudy home pages, 262

generation, 330, 422

generational garbage collection, 403

generator, 196

get method, 105

GET method, 312, 313, 315, 321, 361, 363, 365, 373, 377–378

getAttribute method, 235

getBoundingClientRect method, 236, 339

getContext method, 289

getDate method, 151

getElementById method, 232, 417

getElementsByClassName method, 232

getElementsByTagName method, 232, 233, 243, 418

getFullYear method, 151

getHours method, 151

getImageData method, 345, 346

getItem method, 326, 328

getMinutes method, 151

getMonth method, 151

getPrototypeOf function, 100, 101, 215, 417

getSeconds method, 151

getter, 109, 113, 270

getTime method, 150

getYear method, 151

GitHub, 312

global object, 130

global scope, 43, 170, 210, 259, 354, 355, 417

goalOrientedRobot function, 125

Google, 225

gossip property, 192

grammar, 23, 129, 160

graph, 118, 124, 176, 193, 306, 392, 394, 405

graph layout, 393, 394, 397, 398, 400

graphics, 266, 272, 275, 287–289, 295, 305, 306

GraphNode class, 394, 400

grave accent, see backtick gravity, 282

greater than, 16

greed, 156–157

grep, 368

grid, 266, 273, 278–279, 330, 422

Group class, 113, 114, 126, 197, 411, 412

groupBy function, 95

grouping, 13, 29, 149, 155, 413

groups (exercise), 113, 114, 411, 412

H

h1 (HTML tag), 222, 235

hack, 173

handleAction function, 382

hard disk, 175, 181, 184

hard drive, 12, 325, 327, 353, 387

hard-coding, 231, 307

has method, 105, 113

hash mark character, 214, 336

hasOwnProperty method, 105, 215, 417

head (HTML tag), 222, 223, 228

head property, 228

header, 313, 316, 360, 373

headers property, 315, 316, 329

height property, 350, 423

help text example, 257

hexadecimal numbers, 153, 314, 336, 346

Hières-sur-Amby, 183

hidden element, 238, 262

higher-order functions, see function, higher-order

history, 5, 349

historyUpdateState function, 346

Hoare, C.A.R., 82

Hooke’s law, 395

hooligan, 375

Host header, 313

hot code, 392

href attribute, 222, 232, 235

HTML, 221, 312, 326, 369

notation 221

structure 227

html (HTML tag), 223, 228

HTTP, 219–221, 311–317, 366, 367, 369, 373,

client, 361, 367, 372

server, 360, 363, 375, 381

http package, 360–361

HTTPS, 221, 317, 361

https package, 361

human language, 23

Hypertext Markup Language, see HTML

Hypertext Transfer Protocol, see HTTP

hyphen character, 13, 147, 238

I

id attribute, 232, 239, 323

idempotence, 189, 366, 425

identifier, 204

identity, 65

if keyword, 28, 162

chaining, 29, 34, 408

If-None-Match header, 374, 380, 385

image, 233, 258, 287, 313

imagination, 265

IME (input method editor), 252

img (HTML tag), 222, 233, 237, 258, 287, 295, 296, 345

immutable, 65, 120, 270, 335, 336, 342, 346, 423

implements (reserved word), 26

import keyword, 173

in operator, 64, 105

includes method, 68, 69, 399, 411

indentation, 32

index, 61

index property, 149

index.html file, 381

index.js file, 355

indexOf method, 71, 73, 94, 113, 146, 158, 411

infinite loop, 33, 47, 139, 409

infinity, 14

infrastructure, 169

inheritance, 100, 111–112, 139, 365

INI file, 160

ini package, 169, 173, 175, 356

initialization, 258

inline caching, 403, 404

inline element, 235, 237

inlining, 400

inner function, 44, 418

inner loop, 154

innerHeight property, 257

innerWidth property, 257

input, 134, 247, 266, 319, 353, 378

input (HTML tag), 257, 318, 322, 323, 325, 341, 345

input event, 322

insertBefore method, 232, 233

installation, 169

instance, 101

instanceof operator, 112, 139

instructions, 3, 391

integers, 13

integration, 145, 230

interface, 98

canvas, 287, 289

design, 54, 145, 150, 155, 158, 229, 230, 272, 290

HTTP, 316, 373

module, 168–172, 175, 315, 356

object, 105, 106, 109, 114, 126, 189, 269, 301, 322, 335

interface (reserved word), 26

internationalization, 162

internet, 160, 220, 221, 224

Internet Explorer, 225

interpolation, 15

interpretation, 7, 170, 207–208, 212, 391

interview question, 37

inversion, 147

invoking (of functions), see function application

IP address, 221, 311, 313

isDirectory method, 366, 425

isEven (exercise), 56, 408

isolation, 97, 167, 170, 224

iterable interface, 107, 412

iterator, 196

iterator interface, 106, 107, 114, 398

J

Jacques, the weresquirrel, 60

Java, 5

JavaScript, 5

availability of, 2

flexibility of, 6

history of, 5, 219

in HTML, 223

syntax, 23

uses of, 6

versions of, 6

weaknesses of, 6

JavaScript console, 7, 16, 27, 134, 138, 330, 354

JavaScript Object Notation, see JSON

join method, 94, 104, 356

journal, 60, 62, 64, 66, 69

JOURNAL data set, 68

journalEvents function, 69

JSON, 77, 175, 184, 193, 315, 328, 373, 386, 425

json method, 315

JSON.parse function, 77, 426

JSON.stringify function, 77

JSX, 384

jump, 4

jump-and-run game, 265

jumping, 266, 282

just-in-time compilation, 392

K

Kernighan, Brian, 128

key code, 282

key property, 252, 418, 423

keyboard, 26, 247, 251, 266, 281, 282, 285, 319, 320, 322, 349

keyboard bindings (exercise), 349, 423

keyboard focus, see focus

keydown event, 251, 260, 282, 349, 418, 423

keyup event, 251, 282

keyword, 24, 26, 235

Khasekhemwy, 322

kill process, 360

Knuth, Donald, 40

L

label, 295, 307

label (HTML tag), 323, 341

labeling, 323

landscape example, 44

Laozi, 180

lastChild property, 230

lastIndex property, 158–160

lastIndexOf method, 71

Last-Modified header, 313

latency, 174

lava, 266, 267, 275, 278, 280, 305

Lava class, 270, 280

layering, 194, 220

layout, 235–237

laziness, 236

Le Guin, Ursula K., 2

leaf node, 229

leak, 225, 285

learning, 2, 6, 371

left (CSS), 240–242, 244

LEGO, 168

length property

for arrays, 61, 336

for strings, 53, 56, 61, 74, 409

less than, 16

let keyword, 24, 25, 43, 65, 75, 76, 130

level, 266, 267, 273, 275, 284

Level class, 267

lexical scoping, 44

library, 230, 334, 356, 357

license, 169

line, 24, 32, 161, 287, 289–294, 307, 420

line break, 14, 161

line comment, 35, 156

line drawing, 350, 424

line width, 290, 297

lines of code, 211

lineTo method, 290–291

lineWidth property, 290

link (HTML tag), 277

linked list, 79, 410, 426

links, 222, 230–231, 251, 252, 344

linter, 173

Liskov, Barbara, 96

list (exercise), 79, 410

listen method, 360

listening (TCP), 220, 360

literal expression, 23, 146, 206, 208

live data structure, 227, 233, 240, 419

live view, 372, 373, 387, 426

lives (exercise), 285

load event, 258, 295–296, 303, 326, 421

LoadButton class, 344

local binding, 48, 215, 409

local scope, 43, 212

localhost, 360

localStorage object, 326–327, 383

locked box (exercise), 141, 413

logging, 133

logical operators, 17

long polling, 372–374, 378, 380, 385

loop, 4, 30, 32, 37, 38, 50, 69, 85, 90, 91, 160, 189, 408, 409, 420

termination of, 33

loop body, 31, 85

lycanthropy, 60, 66

M

machine code, 3, 213, 391

macro-optimization, 406

magic, 99, 203

mailRoute array, 123

maintenance, 169

malicious script, 224

man-in-the-middle, 317

map, 272, 321

map (data structure), 104

Map class, 105, 109, 195

map method, 88, 91, 94, 99, 104, 120, 191, 268, 340

Marcus Aurelius, 246

match method, 149, 159

matching, 146, 151, 152, 158, 164

algorithm, 152–154

Math object, 56, 61, 75

Math.abs function, 76, 424

Math.acos function, 75

Math.asin function, 75

Math.atan function, 75

Math.ceil function, 76, 278, 302–303

Math.cos function, 75, 241, 242, 421

mathematics, 50, 86

Math.floor, 76, 122, 278, 302–303

Math.max function, 27, 61, 74, 75, 302

Math.min function, 27, 56, 75, 302

Math.PI constant, 75, 293

Math.random function, 75, 122, 271, 330, 404

Math.round function, 76

Math.sin function, 75, 241, 242, 271, 281

Math.sqrt function, 68, 75, 411

Math.tan function, 75

Matrix class, 107–108, 335

matrix example, 107–108, 111

MatrixIterator class, 108

max-height (CSS), 275–276

maximum, 27, 75, 90

max-width (CSS), 275–276

McConnell, Steve, 390

Meadowfield, 117

measurement, 397

measuring, 399

measuring a robot (exercise), 125, 412

media type, 317, 329, 365

meetups, JavaScript, 371

memory, 3, 11

call stack, 24

organization, 12, 47, 60, 65, 77

persistence, 387

speed, 181, 213, 400, 402, 406

structure sharing, 79

mesh, 221

message event, 259

meta key, 252

metaKey property, 252, 349

method, 62, 100, 101

array, 71

HTTP, 312, 317, 360, 367, 373, 375

interface, 98

method attribute, 313

method call, 98

method property, 315

methods object, 363

micro-optimization, 397, 399, 406

Microsoft, 225

Middle East, graph of, 393

mime package, 365

MIME type, 329, 365

mini application, 326

minifiers, 175

minimalism, 265

minimum, 27, 56, 75

minimum (exercise), 56, 408

minus, 13, 165

Miró, Joan, 332

mirror, 298, 308, 421

mirroring, 297–298

MKCOL method, 368–369, 425

mkdir function, 368–369, 425

modification date, 366

modifier key, 252

modular robot (exercise), 177, 414

modularity, 97, 334

module, 168, 169, 177, 272, 355, 356, 375

design, 175

module loader, 355

module object, 172

module system, 169

modulo (remainder) operator, 14, 33, 297, 407, 408, 418, 420

Mongolian vowel separator, 162

monster (exercise), 285, 419

Mosaic, 225

motion, 266

mouse, 26

button, 249, 250, 253

cursor, 253

mouse trail (exercise), 262, 418

mousedown event, 250, 253, 255, 337, 338, 422

mousemove event, 254, 260–262, 338, 350, 418

mouseup event, 253–255

moveTo method, 290, 293

Mozilla, 225

multiple attribute, 324, 325

multiple-choice, 318–319, 323, 324

multiplication, 13, 269–270, 280

multiplier function, 49

music, 265

mutability, 63, 65, 120

N

name attribute, 320, 324

namespace, 75

naming, 4, 5, 25–26

NaN (not a number), 14, 17, 18, 130

negation, 16, 17

neighbor, 330, 422

neighbors property, 190

nerd, 158

nesting

of arrays, 67

of expressions, 23, 205

of functions, 44

of loops, 38, 408

of objects, 228, 231

in regular expressions, 154

of scope, 44

Netscape, 5, 225

network, 182, 219, 372

abstraction, 194, 316

protocol, 220

reliability, 188

security, 317

speed, 174, 181, 353

network function, 194

new operator, 101

newline character, 14, 38, 147, 156, 161, 268, 422

next method, 107, 197, 412

nextSibling property, 230

Nietzsche, Friedrich, 226

node, 228, 229

node program, 354

node-fetch package, 361

Node.js, 6, 7, 27, 171, 183, 353–369, 372, 373, 375, 387, 398

NodeList type, 230, 239

node_modules directory, 355, 356

nodeName property, 243

nodeType property, 229, 418, 419

nodeValue property, 231

nonbreaking space, 162

normalizing, 396

not a number (NaN), 14, 17, 18, 129

notation, 173

note-taking example, 327

notification, 372

NPM, 169, 171, 173, 174, 176, 177, 355–358, 365, 375, 376, 387, 415

npm program, 356, 357, 365

null, 18, 19, 51, 61, 77, 80, 134

number, 12, 65, 146, 165, 414

conversion to, 19, 28

notation, 12–13

precision of, 13

representation, 12

special values, 14

Number function, 28, 35

number puzzle example, 50–52

Number.isNaN function, 29

O

object, 59, 63–65, 97, 112

creation, 77, 101, 328, 401, 403

identity, 65

as map, 272

as module, 169

mutability, 65

property, 27, 61, 75, 76, 99

representation, 77

Object prototype, 99, 100

object shape, 404

Object.assign function, 328, 336

Object.create function, 100, 104, 211

Object.keys function, 64, 80, 195, 410, 417

object-oriented programming, 97, 101, 105, 106, 111, 119, 175

Object.prototype, 104

observation, 399

obstacle, 277, 278

offsetHeight property, 235, 236

offsetWidth property, 235

on method, 362

onclick attribute, 224, 248

onclick property, 337

OpenGL, 289

opening tag, 222

operator, 13, 16, 19, 204, 210, 404

application, 13

optimization, 50, 55, 236, 260, 266, 275, 306, 308, 359, 392, 398–400, 403, 406, 426

option (HTML tag), 319, 324, 425

optional, in pattern, 148

optional arguments, 48, 78

options property, 324

ordering, 220

ordinal package, 171–172

organic growth, 167

organization, 167

outline, 289

output, 16, 26, 27, 133, 134, 211, 353, 422

overflow (CSS), 275–276

overflow, with numbers, 12

overlap, 278

overlay, 238

overriding, 103, 105, 111, 415

overwriting, 367, 369, 378

P

p (HTML tag), 222, 235

package, 168, 171, 355, 357

package (reserved word), 26

package manager, 169

package.json file, 357

padding (CSS), 274

page reload, 258, 321, 326

pageX property, 253, 255

pageXOffset property, 236

pageY property, 253, 255

pageYOffset property, 236, 257

Palef, Thomas, 265

panning, 339

paragraph, 222

parallelism, 182, 313

parameter, 27, 42, 43, 46–48, 74, 76, 99, 131, 172

parent node, 249

parentheses

arguments, 23, 41, 46, 85, 204

expression, 13

in regular expressions, 149, 151, 152, 162, 413

statement, 27, 29, 31, 33

parentNode property, 230

parse function, 207

parseApply function, 206

parseExpression function, 205

parseINI function, 161, 168

parsing, 77, 129, 161, 203–206, 208, 211, 223, 227, 364, 380

password, 317

password field, 318

path

canvas, 290–293, 420

closing, 291

file system, 355, 363

URL, 312, 315, 363, 364, 373, 375

path package, 365

pathfinding, 123, 176, 193, 343

pathfinding (exercise), 405, 406, 426

patience, 350

pattern, 145–147, 157

pausing (exercise), 285, 419

pea soup, recipe analogy, 84

peanuts, in weresquirrel example, 70–71

percent sign, 314

percentage, 94, 257

performance, 154, 174, 212, 236, 266, 306, 359, 391, 393, 397, 399

period character, 27, 61, 74, 147, 156, 165, 336

persistence, 326, 372, 387, 425

persistent data structure, 119, 120, 126, 132, 335, 342, 346, 419

persistent group (exercise), 126

persistent map (exercise), 413

PGroup class, 126, 413

phase, 271, 281

phi coefficient, 66–68

phi function, 68, 76

phone, 252

physics, 277, 281, 393, 418

physics engine, 278

pi, 13, 75, 241, 271, 293

PI constant, 75, 242

pick function, 343

picture, 287, 288, 296, 306, 334, 346

Picture class, 335, 345

picture property, 335

PictureCanvas class, 337, 349

pictureFromImage function, 345

pie chart example, 294, 295, 307, 420

ping request, 190

pink, 336

pipe analogy, 220

pipe character, 152, 414

pipe method, 364, 367

pipeline, 175

pixel, 235, 242, 253, 267, 273, 288, 289, 295, 296, 302, 306, 308, 333, 335, 339, 342, 343, 345, 350, 423

pixel art, 296

PixelEditor class, 340, 347, 349

pizza, in weresquirrel example, 67

platform game, 265, 285

Plauger, P.J., 128

player, 265–267, 275, 278, 281, 284, 296, 303, 305

Player class, 270, 281

plus character, 13, 148, 165

pointer, 230

pointer events, 253–256, 337

pointerPosition function, 338

polling, 247

pollTalks function, 385

polymorphism, 105–106

pop method, 62, 71

Popper, Karl, 234

port, 220, 311, 360

pose, 296

position, of elements on screen, 236

position (CSS), 240, 244, 257, 266, 275

POST method, 313, 314, 321, 374

postMessage method, 259

power example, 42, 48, 50

precedence, 13, 17, 239

predicate function, 88, 92, 95

Prefer header, 374, 380, 385

premature optimization, 50

preventDefault method, 251, 256–258, 282, 321, 339, 423

previousSibling property, 230

primitiveMultiply (exercise), 141, 413

privacy, 225

private (reserved word), 26

private properties, 98, 141–142

process object, 354–355, 364–365

processor, 181, 400

profiling, 50, 399

program, 2, 23, 28

program size, 83, 84, 164, 272

programming, 1

difficulty of, 2

history of, 3

joy of, 1, 2

Programming Is Terrible, 166

programming language, 1–2

creating, 203, 213

DOM, 229

history of, 3

machine language and, 391

Node.js and, 354

power of, 5

programming style, 3, 24, 32, 35, 272

progress bar, 256

project chapter, 117, 203, 265, 333, 371

promise, 200, 416

Promise class, 186, 187, 189, 195, 197, 198, 200, 315, 326, 359, 361, 363, 386, 416

Promise.all function, 190, 199, 200, 416

Promise.reject function, 187

Promise.resolve function, 186, 190

promises package, 359

promptDirection function, 139

promptInteger function, 134

propagation, of events, 249, 250, 257, 258

proper lines (exercise), 350, 424

property

access, 27, 61, 129, 348, 403

assignment, 63

definition, 63, 66, 109

deletion, 63, 98

inheritance, 99, 101, 103

model of, 63

naming, 105–107

testing for, 64

protected (reserved word), 26

protocol, 220, 221, 311–312

prototype, 99–104, 111, 211, 215, 417, 426

diagram, 103

prototype property, 101

pseudorandom numbers, 75

public (reserved word), 26

public properties, 98

public space (exercise), 369, 425

publishing (packages), 358

punch card, 3

pure function, 55, 79, 88, 175, 330, 422

push method, 62, 69, 71, 411, 426

pushing data, 372

PUT method, 312–313, 363, 367, 373, 378, 425

Pythagorean theorem, 411, 423

Python, 391

Q

quadratic curve, 292

quadraticCurveTo method, 292, 420

query string, 314, 374, 380

querySelector method, 240, 417

querySelectorAll method, 239, 324

question mark, 18, 148, 157, 314

queue, 198

quotation mark, 14, 165

quoting

in JSON, 77

of object properties, 63

quoting style (exercise), 165, 413

R

rabbit example, 98, 100–102

radians, 242, 293, 298

radio buttons, 318, 323

radius, 350, 423

radix, 11

raising (exceptions), 135

random numbers, 75, 271

random-item package, 414

randomPick function, 122

randomRobot function, 122

range, 88, 147, 148

range function, 5, 78, 409

Range header, 316

ray tracer, 306

readability, 4, 5, 35, 50, 54, 135, 167, 208, 276, 307

readable stream, 361, 362, 364, 378

readAsDataURL method, 345

readAsText method, 326

readdir function, 359, 366, 425

readdirSync function, 425

read-eval-print loop, 354

readFile function, 172, 358, 425

readFileSync function, 359, 424

reading code, 6, 117

readStorage function, 184

readStream function, 378, 379

real-time events, 247

reasoning, 17

recipe analogy, 84

record, 62

rect (SVG tag), 288

rectangle, 266, 278, 289, 307, 342

rectangle function, 342, 423

recursion, 47, 50, 56, 80, 189, 195, 205, 206, 208, 231, 243, 300, 394, 408, 410, 413, 416, 418

reduce method, 89, 91, 94, 95, 340, 411

redundancy, 397

ReferenceError type, 215

RegExp class, 146, 157, 424

regexp golf (exercise), 164

regular expressions, 145–165, 206, 368, 375, 376, 417, 424

alternatives, 152

backtracking, 153

boundary, 151

creation, 146, 157

escaping, 146, 158, 414

flags, 149, 155, 157, 414

global, 155, 158, 159

grouping, 149, 155

internationalization, 162

matching, 152, 158

methods, 146, 150, 158

repetition, 148

rejecting (a promise), 187, 189, 198

relative path, 172, 224, 355, 363, 425

relative positioning, 240, 241

relative URL, 315

remainder (modulo) operator, 14, 33, 297, 407, 408, 418, 420

remote access, 363

remote procedure call, 316

removeChild method, 232

removeEventListener method, 248, 419

removeItem method, 326

rename function, 359

rendering, 289

renderTalk function, 384

renderTalkForm function, 385

renderUserField function, 383

repeat method, 73, 257

repeating key, 251

repetition, 52, 148, 154, 157, 260

replace method, 155, 165, 413

replaceChild method, 233, 418

replaceSelection function, 322

reportError function, 383

repulsion, 393, 395

request, 185, 189, 220, 312, 313, 321, 360, 361, 367, 372

request function, 189, 361, 362

request type, 185

requestAnimationFrame function, 241, 258, 260, 283, 308, 418

requestType function, 190

require function, 171, 172, 178, 355, 356, 365, 375

reserved words, 26

resolution, 172, 355

resolve function, 364

resolving (a promise), 186, 187, 189, 198

resource, 220, 221, 312, 313, 317, 363, 377

response, 185, 189, 312, 313, 316, 360, 364, 366

Response class, 315

responsiveness, 247, 353, rest parameters, 74

restore method, 299, 300

result property, 326

retry, 189

return keyword, 42, 47, 101, 196, 408, 411

return value, 27, 42, 134, 185, 410

reuse, 54, 112, 167–169, 356

reverse method, 79

reversing (exercise), 79, 409

rgb (CSS), 274

right-aligning, 243

rmdir function, 366, 368

roadGraph object, 118

roads array, 117

roads module (exercise), 177, 415

robot, 117, 119, 121, 123, 125, 177

robot efficiency (exercise), 125, 412

robustness, 373

root, 229

rotate method, 298, 300

rotation, 307, 420

rounding, 76, 134, 278, 279, 302, 424

router, 372, 375

Router class, 375, 376

routeRequest function, 194

routeRobot function, 123

routing, 192

rows, in tables, 243

Ruby, 391

rules (CSS), 238, 239

run function, 211

runAnimation function, 283, 285

runGame function, 284, 285

runLayout function, 396

runLevel function, 283, 285

running code, 7

runRobot function, 121, 412

run-time error, 132–134, 140, 417

Rust (programming language), 391

S

Safari, 225

sandbox, 7, 59, 224, 227, 316

save method, 299, 300

SaveButton class, 344

scalar replacement of aggregates, 400, 402

scale constant, 337–339

scale method, 297, 299

scaling, 273, 296, 297, 303, 421

scalpel (exercise), 200, 416

scheduling, 197, 354

scientific notation, 13, 165

scope, 43, 44, 48, 168, 170–173, 208, 210, 214, 215, 417

script (HTML tag), 223, 224, 258

SCRIPTS data set, 87, 89, 92, 93, 95

scroll event, 256, 260

scrolling, 251, 256–257, 275–276, 282, 301

search method, 158

search problem, 124, 152, 154, 232, 368, 405

search tool (exercise), 368, 424

section, 161

Secure HTTP, 221, 317, 361

security, 224, 225, 316, 317, 325, 327, 364, 375

select (HTML tag), 319, 324, 327, 334, 340, 425

selected attribute, 324

selection, 322

selectionEnd property, 322

selectionStart property, 322

selector, 239

self-closing tag, 222

semantic versioning, 357

semicolon, 23, 24, 33, 237

send method, 185, 188

sendGossip function, 191

sep binding, 364–365

sequence, 148

serialization, 77

server, 220, 221, 311–313, 315, 316, 353, 360, 362, 363, 372, 375

session, 328

sessionStorage object, 328

set, 146, 147, 229

Set (data structure), 113, 126

Set class, 113, 126, 413

set method, 105

setAttribute method, 235, 337

setInterval function, 260, 296

setItem method, 326

setter, 110

setTimeout function, 184, 197, 259, 260, 380, 386

shape, 287, 290, 291, 293, 295, 307

shapes (exercise), 307, 420

shared property, 100, 103

SHIFT key, 252, 423

shift method, 71

shiftKey property, 252

short-circuit evaluation, 20, 51, 209, 411

SICP, 202

side effect, 24, 27, 34, 42, 54, 65, 79, 88, 159, 175, 199, 230, 232, 233, 236, 290, 299, 314, 334, 335

sign, 12, 165, 414

sign bit, 12

signal, 11

simplicity, 213

simulation, 119, 121, 265, 270, 330, 393, 418

sine, 75, 241, 271, 281

single-quote character, 14, 165, 224

singleton, 126

skill, 333

SkillShareApp class, 386

skill-sharing project, 371–373, 375, 381

skipSpace function, 206, 214

slash character, 13, 35–36, 146, 156, 315, 364, 425

slice method, 72, 73, 88, 233, 409, 416

slope, 424

sloppy programming, 261

smooth animation, 241

SMTP, 220

social factors, 349

socket, 372–373

some method, 92, 95, 191, 376, 426

sorting, 229

source property, 158

special form, 203, 208

special return value, 134, 135

specialForms object, 208

specificity, 239

speed, 1, 2, 308, 421

SpiderMonkey, 400

spiral, 307, 420

split method, 118, 268

spread, 74, 336

spread operator, 274

spring, 393, 395

sprite, 296, 303–304

spy, 256

square, 28

square brackets, 60, 61, 74, 76, 107, 147, 324, 328, 409

square example, 41–42, 45, 46

square root, 68, 75, 411

src attribute, 222, 224

stack, see call stack stack overflow, 47, 50, 56, 408

stack trace, 136

staged compilation, 392

standard, 5, 26, 35, 88, 136, 162, 349, 354, 355

standard environment, 26

standard output, 354, 362–363

standards, 219, 225

star, 307, 420 Star Trek insignia, 292

startPixelEditor function, 347

startState constant, 347

startsWith method, 364

stat function, 359, 365, 366, 425

state

of application, 275, 334, 342, 346, 347, 388

in binding, 24, 31, 32, 34, 400

of canvas, 289, 299

in iterator, 197

in objects, 119, 268, 301

transitions, 198, 336, 337

statement, 23, 24, 28, 31, 32, 42, 63

static (reserved word), 26

static file, 373, 376

static method, 110, 113, 268, 413

static typing, 403

Stats type, 366

statSync function, 425

status code, 312, 354–355

status property, 315, 383

stdout property, 362–363

stopPropagation method, 250

storage function, 187

stream, 220, 361–363, 364, 367, 378

strict mode, 130

string, 14, 60, 62, 65, 92

indexing, 56, 72, 74, 92, 149

length, 37, 92

methods, 73, 149

notation, 14

properties, 72

representation, 15

searching, 73

String function, 28, 105

stroke method, 290–292

strokeRect method, 289, 421

strokeStyle property, 290

strokeText method, 295

stroking, 289, 290, 295, 306

strong (HTML tag), 235, 237

structure, 168, 222, 227, 334 Structure and Interpretation of Computer Programs, 202

structure sharing, 79

style, 237

style (HTML tag), 238, 239

style attribute, 237–239, 273

style sheet, see CSS subclass, 111

submit, 318, 320, 321

submit event, 321, 384, 425

substitution, 54

subtraction, 13, 113

sum function, 5, 78

summing (exercise), 78, 409

summing example, 4, 83, 89, 211

superclass, 111

survey, 294

Sussman, Gerald, 202

SVG, 287–289, 305, 306

swapping bindings, 424

swipe, 342

switch keyword, 34

symbiotic relationship, 183

symbol, 106

Symbol function, 106

Symbol.iterator symbol, 107

SymmetricMatrix class, 111

synchronization, 387, 426

synchronous programming, 182, 195, 359, 368

syncState method, 335, 338, 340, 341, 349, 426

syntax

of Egg, 203, 204

error, 26, 129, 130

expression, 23

function, 42, 45

identifier, 26

number, 12, 165

object, 63

operator, 13

statement, 24, 26, 28–34, 135

string, 14

syntax tree, 204–205, 207, 228–229

SyntaxError type, 206

T

tab character, 14, 32

TAB key, 320

tabbed interface (exercise), 262, 419

tabindex attribute, 252, 320, 349

table (HTML tag), 243, 266, 274, 422

table example, 417

tableFor function, 68

tables, 67, 68, 274

tags, 221–222, 227, 239, see also names of specific tags

talk, 371, 372, 377–379

talkResponse method, 380

talksAbout function, 231

talkURL function, 383

Tamil, 87

tampering, 317

tangent, 75

target property, 250

task management example, 71

TCP, 220, 221, 311, 373

td (HTML tag), 243, 274

Tef, 166

temperature example, 110

template, 171, 388, 426

template literals, 15

tentacle (analogy), 25, 63, 65

terminal, 354

termite, 183

ternary operator, 18, 20, 209

test method, 146

test runners, 132

test suites, 132

testing, 125, 132

text, 14, 221, 222, 227, 229, 295, 305–307, 322, 324, 358, 422

text field, 257, 318, 319, 322

text method, 315

text node, 229, 231, 233, 419

text wrapping, 305

text-align (CSS), 243

textAlign property, 295, 420

textarea (HTML tag), 260, 318, 322, 327, 330, 425

textBaseline property, 295, 420

textContent property, 418, 422

TEXT_NODE code, 229, 419

textScripts function, 94, 411

th (HTML tag), 243

then method, 186–188, 191, 416

theory, 133

this binding, 62, 98–99, 101, 130

thread, 182, 183, 198, 259

throw keyword, 135, 136, 139, 141, 413

tile, 303

time, 147, 148, 150, 184, 241, 261, 277, 278, 280, 283, 303, 346

time zone, 150

timeline, 182, 197, 223, 241, 247, 258

timeout, 188, 259, 373, 374, 380

Timeout class, 189

times method, 269

timing, 396

title, 382

title (HTML tag), 222, 223

toDataURL method, 344

toLowerCase method, 62, 243

tool, 145, 164, 175, 334, 339, 340, 342–344, 347, 350, 357

tool property, 335

ToolSelect class, 340

top (CSS), 240–242, 244

top-level scope, see global scope

toString method, 99, 100, 103–105, 346, 362

touch, 255, 334

touchend event, 255

touches method, 278

touches property, 255, 339

touchmove event, 255, 339, 350

touchstart event, 255, 337, 339

toUpperCase method, 62, 132, 243, 362

tr (HTML tag), 243, 274

trackKeys function, 282, 285

transform (CSS), 287

transformation, 297–299, 308, 420

translate method, 298, 299

Transmission Control Protocol, 220, 221, 311, 373

transparency, 289, 296, 346

transpilation, 213

trapezoid, 307, 420

traversal, 152

tree, 100, 204, 229

treeGraph function, 394

trial and error, 133, 282, 293

triangle (exercise), 37, 407

trigonometry, 75, 241

trim method, 73, 268

true, 16

trust, 224

try keyword, 136, 137, 190, 413, 422

type, 12, 16, 112

type attribute, 318, 321

type checking, 131, 174

type coercion, 18, 19, 28

type observation, 392, 401, 403

type property, 204, 249

type variable, 131

typeof operator, 16, 80, 410

TypeScript, 131–132

typing, 260

typo, 129

U

Ullman, Ellen, xx

unary operator, 16, 23

uncaught exception, 138, 188

undefined, 18, 19, 25, 42, 47, 61, 63, 77, 129, 130, 134

underline, 237

underscore character, 26, 35, 98, 151, 157

undo history, 346, 347

UndoButton class, 347

Unicode, 15, 17, 87, 92, 147, 162, 163

unicycling, 371

Uniform Resource Locator, see URL uniformity, 204

uniqueness, 239

unit (CSS), 242, 257

Unix, 366–368

Unix time, 150

unlink function, 359, 366

unshift method, 71

unwinding the stack, 135

upcasing server example, 362

updated method, 378, 381, 425

updateState function, 336

upgrading, 169

upload, 325

URL, 221, 224, 288, 313, 315, 317, 360, 373, 383

URL encoding, 314

url package, 364, 380

urlToPath function, 364

usability, 251

use strict, 130

user experience, 247, 320, 372, 383

user interface, 138, 334

users’ group, 371

UTF-8, 358, 359

UTF-16, 15, 92

V

V8, 398

validation, 134, 140, 203, 277, 321, 378, 379

value, 12, 186

value attribute, 318, 322, 324

var keyword, 25, 43, 76

variables, see also binding

Vec class, 113, 268, 269, 280, 394, 396, 421

vector, 394, 400

vector (exercise), 113, 411

vector graphics, 295

verbosity, 46, 182

version, 169, 222, 312, 357, 398

viewport, 275–277, 301, 302, 305

VillageState class, 119

virtual keyboard, 252

virtual world, 117, 119, 121

virus, 224

vocabulary, 41, 84

void operator, 26

volatile data storage, 12

W

waitForChanges method, 380

waiting, 184

walking, 303

warning, 357

wave, 271, 280, 281

web, see World Wide Web

web application, 5, 326, 333

web browser, see browser

web page, 174

web worker, 259

WebDAV, 369

webgl (canvas context), 289

website, 224, 225, 313, 353, 369, 371

WebSockets, 373

weekDay module, 169–170

weekend project, 369

weresquirrel example, 60, 62, 64, 66, 69, 71

while loop, 4, 30, 32, 53, 160

whitespace

in HTML, 231, 340, 419

indentation, 32

matching, 147, 162

syntax, 204, 206, 214, 417

trimming, 73, 268

in URLs, 373–374

Why’s (Poignant) Guide to Ruby, 22

width property, 350, 423

window, 250, 255, 258

window object, 248

with statement, 131

word boundary, 151

word character, 147, 151, 162

work list, 124, 343

workbench (exercise), 330, 422

world, of a game, 265

World Wide Web, 5, 77, 219, 221, 224, 225, 311

writable stream, 360–363, 364

write method, 360, 361

writeFile function, 359, 361, 425

writeHead method, 360

writing code, 6, 117

writing system, 87

WWW, see World Wide Web

X

XML, 230, 288

XML namespace, 288

xmlns attribute, 288

Y

yield (reserved word), 26

yield keyword, 197

your own loop (example), 95

Yuan-Ma, 10, 352

Z

Zawinski, Jamie, 144

zero-based counting, 56, 61, 150

zeroPad function, 54

zigzag shape, 420

zooming, 305