FreePic2Pdf_bkmk.txt

1. The JavaScript language	1
	1.1 An introduction	2
		1.1.1 An Introduction to JavaScript	3
		1.1.2 Manuals and specifications	9
		1.1.3 Code editors	12
		1.1.4 Developer console	16
	1.2 JavaScript Fundamentals	20
		1.2.1 Hello, world!	21
		1.2.2 Code structure	27
		1.2.3 The modern mode, "use strict"	33
		1.2.4 Variables	37
		1.2.5 Data types	47
		1.2.6 Interaction: alert, prompt, confirm	57
		1.2.7 Type Conversions	64
		1.2.8 Basic operators, maths	74
		1.2.9 Comparisons	88
		1.2.10 Conditional branching: if, '?'	95
		1.2.11 Logical operators	105
		1.2.12 Nullish coalescing operator '??'	116
		1.2.13 Loops: while and for	123
		1.2.14 The "switch" statement	137
		1.2.15 Functions	143
		1.2.16 Function expressions	158
		1.2.17 Arrow functions, the basics	168
		1.2.18 JavaScript specials	174
	1.3 Code quality	183
		1.3.1 Debugging in the browser	184
		1.3.2 Coding Style	193
		1.3.3 Comments	205
		1.3.4 Ninja code	213
		1.3.5 Automated testing with Mocha	221
		1.3.6 Polyfills and transpilers	235
	1.4 Objects: the basics	240
		1.4.1 Objects	241
		1.4.2 Object references and copying	256
		1.4.3 Garbage collection	266
		1.4.4 Object methods, "this"	277
		1.4.5 Constructor, operator "new"	287
		1.4.6 Optional chaining '?.'	298
		1.4.7 Symbol type	306
		1.4.8 Object to primitive conversion	315
	1.5 Data types	323
		1.5.1 Methods of primitives	324
		1.5.2 Numbers	331
		1.5.3 Strings	347
		1.5.4 Arrays	361
		1.5.5 Array methods	378
		1.5.6 Iterables	402
		1.5.7 Map and Set	414
		1.5.8 WeakMap and WeakSet	425
		1.5.9 Object.keys, values, entries	436
		1.5.10 Destructuring assignment	441
		1.5.11 Date and time	456
		1.5.12 JSON methods, toJSON	472
	1.6 Advanced working with functions	487
		1.6.1 Recursion and stack	488
		1.6.2 Rest parameters and spread syntax	505
		1.6.3 Variable scope, closure	514
		1.6.4 The old "var"	533
		1.6.5 Global object	542
		1.6.6 Function object, NFE	546
		1.6.7 The "new Function" syntax	557
		1.6.8 Scheduling: setTimeout and setInterval	563
		1.6.9 Decorators and forwarding, call/apply	575
		1.6.10 Function binding	591
		1.6.11 Arrow functions revisited	603
	1.7 Object properties configuration	611
		1.7.1 Property flags and descriptors	612
		1.7.2 Property getters and setters	622
	1.8 Prototypes, inheritance	630
		1.8.1 Prototypal inheritance	631
		1.8.2 F.prototype	644
		1.8.3 Native prototypes	653
		1.8.4 Prototype methods, objects without __proto__	663
	1.9 Classes	673
		1.9.1 Class basic syntax	674
		1.9.2 Class inheritance	687
		1.9.3 Static properties and methods	705
		1.9.4 Private and protected properties and methods	714
		1.9.5 Extending built-in classes	726
		1.9.6 Class checking: "instanceof"	731
		1.9.7 Mixins	739
	1.10 Error handling	748
		1.10.1 Error handling, "try...catch"	749
		1.10.2 Custom errors, extending Error	766
	1.11 Promises, async/await	776
		1.11.1 Introduction: callbacks	777
		1.11.2 Promise	785
		1.11.3 Promises chaining	797
		1.11.4 Error handling with promises	809
		1.11.5 Promise API	817
		1.11.6 Promisification	826
		1.11.7 Microtasks	833
		1.11.8 Async/await	839
	1.12 Generators, advanced iteration	850
		1.12.1 Generators	851
		1.12.2 Async iteration and generators	865
	1.13 Modules	877
		1.13.1 Modules, introduction	878
		1.13.2 Export and Import	891
		1.13.3 Dynamic imports	903
	1.14 Miscellaneous	909
		1.14.1 Proxy and Reflect	910
		1.14.2 Eval: run a code string	937
		1.14.3 Currying	942
		1.14.4 Reference Type	951
		1.14.5 BigInt	956
		1.14.6 Unicode, String internals	963
2. Browser: Document, Events, Interfaces	967
	2.1 Document	968
		2.1.1 Browser environment, specs	969
		2.1.2 DOM tree	974
		2.1.3 Walking the DOM	985
		2.1.4 Searching: getElement*, querySelector*	998
		2.1.5 Node properties: type, tag and contents	1008
		2.1.6 Attributes and properties	1023
		2.1.7 Modifying the document	1036
		2.1.8 Styles and classes	1061
		2.1.9 Element size and scrolling	1072
		2.1.10 Window sizes and scrolling	1087
		2.1.11 Coordinates	1093
	2.2 Introduction to Events	1109
		2.2.1 Introduction to browser events	1110
		2.2.2 Bubbling and capturing	1126
		2.2.3 Event delegation	1137
		2.2.4 Browser default actions	1151
		2.2.5 Dispatching custom events	1165
	2.3 UI Events	1174
		2.3.1 Mouse events	1175
		2.3.2 Moving the mouse: mouseover/out, mouseenter/leave	1186
		2.3.3 Drag'n'Drop with mouse events	1210
		2.3.4 Pointer events	1222
		2.3.5 Keyboard: keydown and keyup	1231
		2.3.6 Scrolling	1242
	2.4 Forms, controls	1249
		2.4.1 Form properties and methods	1250
		2.4.2 Focusing: focus/blur	1259
		2.4.3 Events: change, input, cut, copy, paste	1272
		2.4.4 Forms: event and method submit	1279
	2.5 Document and resource loading	1284
		2.5.1 Page: DOMContentLoaded, load, beforeunload, unload	1285
		2.5.2 Scripts: async, defer	1296
		2.5.3 Resource loading: onload and onerror	1304
	2.6 Miscellaneous	1312
		2.6.1 Mutation observer	1313
		2.6.2 Selection and Range	1323
		2.6.3 Event loop: microtasks and macrotasks	1341
3. Additional articles	1352
	3.1 Frames and windows	1353
		3.1.1 Popups and window methods	1354
		3.1.2 Cross-window communication	1363
		3.1.3 The clickjacking attack	1375
	3.2 Binary data, files	1384
		3.2.1 ArrayBuffer, binary arrays	1385
		3.2.2 TextDecoder and TextEncoder	1396
		3.2.3 Blob	1400
		3.2.4 File and FileReader	1409
	3.3 Network requests	1417
		3.3.1 Fetch	1418
		3.3.2 FormData	1428
		3.3.3 Fetch: Download progress	1436
		3.3.4 Fetch: Abort	1442
		3.3.5 Fetch: Cross-Origin Requests	1446
		3.3.6 Fetch API	1459
		3.3.7 URL objects	1466
		3.3.8 XMLHttpRequest	1474
		3.3.9 Resumable file upload	1486
		3.3.10 Long polling	1490
		3.3.11 WebSocket	1500
		3.3.12 Server Sent Events	1511
	3.4 Storing data in the browser	1519
		3.4.1 Cookies, document.cookie	1520
		3.4.2 LocalStorage, sessionStorage	1532
		3.4.3 IndexedDB	1540
	3.5 Animation	1560
		3.5.1 Bezier curve	1561
		3.5.2 CSS-animations	1573
		3.5.3 JavaScript animations	1597
	3.6 Web components	1614
		3.6.1 From the orbital height	1615
		3.6.2 Custom elements	1619
		3.6.3 Shadow DOM	1631
		3.6.4 Template element	1637
		3.6.5 Shadow DOM slots, composition	1640
		3.6.6 Shadow DOM styling	1651
		3.6.7 Shadow DOM and events	1658
	3.7 Regular expressions	1664
		3.7.1 Patterns and flags	1665
		3.7.2 Character classes	1671
		3.7.3 Unicode: flag "u" and class \p{...}	1676
		3.7.4 Anchors: string start ^ and end $	1682
		3.7.5 Multiline mode of anchors ^ $, flag "m"	1686
		3.7.6 Word boundary: \b	1690
		3.7.7 Escaping, special characters	1694
		3.7.8 Sets and ranges [...]	1697
		3.7.9 Quantifiers +, *, ? and {n}	1703
		3.7.10 Greedy and lazy quantifiers	1707
		3.7.11 Capturing groups	1718
		3.7.12 Backreferences in pattern: \N and \k<name>	1730
		3.7.13 Alternation (OR) |	1733
		3.7.14 Lookahead and lookbehind	1739
		3.7.15 Catastrophic backtracking	1745
		3.7.16 Sticky flag "y", searching at position	1752
		3.7.17 Methods of RegExp and String	1756
            What is JavaScript?	3
	        What can in-browser JavaScript do?	3
		    What CAN’T in-browser JavaScript do?	4
			What makes JavaScript unique?	5
			Languages “over” JavaScript	5
			Summary	6
			Specification	9
			Manuals	9
			Compatibility tables	9
			IDE	12
			Lightweight editors	12
			Let’s not argue	12
			Google Chrome	16
			Firefox, Edge, and others	17
			Safari	17
			Summary	17
			The “script” tag	21
			Modern markup	21
			External scripts	22
			Summary	23
			Tasks	23
			Statements	27
			Semicolons	27
			Comments	28
			“use strict”	33
			Browser console	34
			Should we “use strict”?	34
			A variable	37
			A real-life analogy	38
			Variable naming	40
			Constants	41
			Name things right	42
			Summary	43
			Tasks	43
			Number	47
			BigInt	48
			String	49
			Boolean (logical type)	49
			The “null” value	50
			The “undefined” value	50
			Objects and Symbols	51
			The typeof operator	51
			Summary	52
			Tasks	52
			alert	57
			prompt	57
			confirm	58
			Summary	58
			Tasks	59
			String Conversion	64
			Numeric Conversion	64
			Boolean Conversion	65
			Summary	66
			Terms: “unary”, “binary”, “operand”	74
			Maths	74
			String concatenation with binary +	75
			Numeric conversion, unary +	76
			Operator precedence	77
			Assignment	77
			Modify-in-place	79
			Increment/decrement	79
			Bitwise operators	81
			Comma	82
			Tasks	82
			Boolean is the result	88
			String comparison	88
			Comparison of different types	89
			Strict equality	90
			Comparison with null and undefined	91
			Summary	92
			Tasks	92
			The “if” statement	95
			Boolean conversion	95
			The “else” clause	96
			Several conditions: “else if”	96
			Conditional operator ‘?’	96
			Multiple ‘?’	97
			Non-traditional use of ‘?’	98
			Tasks	99
			|| (OR)	105
			OR "||" finds the first truthy value	106
			&& (AND)	107
			AND “&&” finds the first falsy value	107
			! (NOT)	109
			Tasks	110
			Comparison with ||	117
			Precedence	118
			Summary	118
			The “while” loop	123
			The “do…while” loop	124
			The “for” loop	124
			Breaking the loop	127
			Continue to the next iteration	127
			Labels for break/continue	128
			Summary	130
			Tasks	130
			The syntax	137
			An example	137
			Grouping of “case”	139
			Type matters	139
			Tasks	140
			Function Declaration	143
			Local variables	143
			Outer variables	144
			Parameters	145
			Default values	146
			Returning a value	148
			Naming a function	150
			Functions == Comments	151
			Summary	152
			Tasks	153
			Function is a value	158
			Callback functions	160
			Function Expression vs Function Declaration	161
			Summary	164
			Multiline arrow functions	169
			Summary	169
			Tasks	170
			Code structure	174
			Strict mode	174
			Variables	175
			Interaction	175
			Operators	176
			Loops	177
			The “switch” construct	177
			Functions	178
			More to come	179
			The “Sources” panel	184
			Console	185
			Breakpoints	185
			The command “debugger”	186
			Pause and look around	186
			Tracing the execution	187
			Logging	188
			Summary	188
			Syntax	193
			Function Placement	197
			Style Guides	198
			Automated Linters	198
			Summary	199
			Tasks	199
			Bad comments	205
			Good comments	207
			Summary	208
			Brevity is the soul of wit	213
			One-letter variables	213
			Use abbreviations	214
			Soar high. Be abstract.	214
			Attention test	214
			Smart synonyms	215
			Reuse names	215
			Underscores for fun	216
			Show your love	216
			Overlap outer variables	216
			Side-effects everywhere!	216
			Powerful functions!	217
			Summary	217
			Why do we need tests?	221
			Behavior Driven Development (BDD)	221
			Development of “pow”: the spec	221
			The development flow	222
			The spec in action	222
			Initial implementation	224
			Improving the spec	224
			Improving the implementation	225
			Nested describe	226
			Extending the spec	228
			Summary	230
			Tasks	231
			Transpilers	235
			Polyfills	235
			Summary	236
			Literals and properties	241
			Square brackets	243
			Property value shorthand	245
			Property names limitations	246
			Property existence test, “in” operator	247
			The "for..in" loop	248
			Summary	250
			Tasks	250
			Comparison by reference	257
			Cloning and merging, Object.assign	258
			Nested cloning	260
			Summary	262
			Reachability	266
			A simple example	266
			Two references	267
			Interlinked objects	267
			Unreachable island	269
			Internal algorithms	270
			Summary	272
			Method examples	277
			“this” in methods	278
			“this” is not bound	279
			Arrow functions have no “this”	281
			Summary	281
			Tasks	281
			Constructor function	287
			Constructor mode test: new.target	288
			Return from constructors	289
			Methods in constructor	290
			Summary	290
			Tasks	291
			The “non-existing property” problem	298
			Optional chaining	299
			Short-circuiting	300
			Other variants: ?.(), ?.[]	301
			Summary	302
			Symbols	306
			“Hidden” properties	307
			Global symbols	309
			System symbols	310
			Summary	310
			Conversion rules	315
			Hints	315
			Symbol.toPrimitive	317
			toString/valueOf	317
			Further conversions	319
			Summary	320
			A primitive as an object	324
			Summary	326
			Tasks	327
			More ways to write a number	331
			toString(base)	332
			Rounding	333
			Imprecise calculations	334
			Tests: isFinite and isNaN	336
			parseInt and parseFloat	338
			Other math functions	339
			Summary	339
			Tasks	340
			Quotes	347
			Special characters	348
			String length	349
			Accessing characters	349
			Strings are immutable	350
			Changing the case	350
			Searching for a substring	350
			Getting a substring	353
			Comparing strings	354
			Summary	356
			Tasks	356
			Declaration	361
			Get last elements with “at”	362
			Methods pop/push, shift/unshift	363
			Internals	365
			Performance	366
			Loops	367
			A word about “length”	368
			new Array()	368
			Multidimensional arrays	369
			toString	369
			Don’t compare arrays with ==	369
			Summary	370
			Tasks	371
			Add/remove items	378
			Iterate: forEach	381
			Searching in array	382
			Transform an array	384
			Array.isArray	390
			Most methods support “thisArg”	390
			Summary	391
			Tasks	392
			Symbol.iterator	402
			String is iterable	404
			Calling an iterator explicitly	404
			Iterables and array-likes	405
			Array.from	405
			Summary	407
			Map	414
			Iteration over Map	415
			Object.entries: Map from Object	416
			Object.fromEntries: Object from Map	417
			Set	418
			Iteration over Set	419
			Summary	419
			Tasks	420
			WeakMap	426
			Use case: additional data	426
			Use case: caching	428
			WeakSet	429
			Summary	430
			Tasks	430
			Object.keys, values, entries	436
			Transforming objects	437
			Tasks	438
			Array destructuring	441
			Object destructuring	445
			Nested destructuring	448
			Smart function parameters	449
			Summary	451
			Tasks	451
			Creation	456
			Access date components	457
			Setting date components	458
			Autocorrection	459
			Date to number, date diff	459
			Date.now()	460
			Benchmarking	460
			Date.parse from a string	462
			Summary	463
			Tasks	464
			JSON.stringify	472
			Excluding and transforming: replacer	475
			Formatting: space	477
			Custom “toJSON”	478
			JSON.parse	479
			Using reviver	480
			Summary	481
			Tasks	481
			Two ways of thinking	488
			The execution context and stack	490
			Recursive traversals	493
			Recursive structures	495
			Summary	498
			Tasks	498
			Rest parameters ...	505
			The “arguments” variable	506
			Spread syntax	507
			Copy an array/object	509
			Summary	509
			Code blocks	514
			Nested functions	515
			Lexical Environment	516
			Garbage collection	521
			Tasks	523
			“var” has no block scope	533
			“var” tolerates redeclarations	534
			“var” variables can be declared below their use	534
			IIFE	536
			Summary	537
			Using for polyfills	543
			Summary	543
			The “name” property	546
			The “length” property	547
			Custom properties	548
			Named Function Expression	549
			Summary	551
			Tasks	552
			Syntax	557
			Closure	557
			Summary	558
			setTimeout	563
			setInterval	564
			Nested setTimeout	565
			Zero delay setTimeout	567
			Summary	568
			Tasks	569
			Transparent caching	575
			Using “func.call” for the context	576
			Going multi-argument	578
			func.apply	580
			Borrowing a method	581
			Decorators and function properties	582
			Summary	582
			Tasks	582
			Losing “this”	591
			Solution 1: a wrapper	591
			Solution 2: bind	592
			Partial functions	594
			Going partial without context	595
			Summary	596
			Tasks	596
			Arrow functions have no “this”	603
			Arrows have no “arguments”	604
			Summary	605
			Property flags	612
			Non-writable	613
			Non-enumerable	614
			Non-configurable	615
			Object.defineProperties	616
			Object.getOwnPropertyDescriptors	617
			Sealing an object globally	617
			Getters and setters	622
			Accessor descriptors	623
			Smarter getters/setters	624
			Using for compatibility	625
			[[Prototype]]	631
			Writing doesn’t use prototype	634
			The value of “this”	635
			for…in loop	636
			Summary	638
			Tasks	638
			Default F.prototype, constructor property	645
			Summary	647
			Tasks	647
			Object.prototype	653
			Other built-in prototypes	654
			Primitives	655
			Changing native prototypes	656
			Borrowing from prototypes	657
			Summary	657
			Tasks	657
			Brief history	664
			"Very plain" objects	664
			Summary	666
			Tasks	667
			The “class” syntax	674
			What is a class?	675
			Not just a syntactic sugar	676
			Class Expression	677
			Getters/setters	678
			Computed names […]	678
			Class fields	679
			Summary	680
			Tasks	681
			The “extends” keyword	687
			Overriding a method	689
			Overriding constructor	690
			Super: internals, [[HomeObject]]	694
			Summary	698
			Tasks	699
			Static properties	707
			Inheritance of static properties and methods	707
			Summary	708
			Tasks	709
			A real-life example	714
			Internal and external interface	715
			Protecting “waterAmount”	716
			Read-only “power”	717
			Private “#waterLimit”	718
			Summary	720
			No static inheritance in built-ins	727
			The instanceof operator	731
			Bonus: Object.prototype.toString for the type	733
			Summary	735
			Tasks	735
			A mixin example	739
			EventMixin	741
			Summary	743
			The “try…catch” syntax	749
			Error object	751
			Optional “catch” binding	752
			Using “try…catch”	752
			Throwing our own errors	753
			Rethrowing	755
			try…catch…finally	757
			Global catch	759
			Summary	760
			Tasks	761
			Extending Error	766
			Further inheritance	768
			Wrapping exceptions	770
			Summary	772
			Tasks	772
			Callback in callback	779
			Handling errors	779
			Pyramid of Doom	780
			Consumers: then, catch	788
			Cleanup: finally	789
			Example: loadScript	791
			Tasks	792
			Returning promises	799
			Example: loadScript	799
			Bigger example: fetch	801
			Summary	804
			Tasks	804
			Implicit try…catch	809
			Rethrowing	810
			Unhandled rejections	811
			Summary	812
			Tasks	812
			Promise.all	817
			Promise.allSettled	819
			Promise.race	820
			Promise.any	821
			Promise.resolve/reject	822
			Summary	823
			Microtasks queue	833
			Unhandled rejection	834
			Summary	834
			Async functions	839
			Await	839
			Error handling	842
			Summary	844
			Tasks	844
			Generator functions	851
			Generators are iterable	853
			Using generators for iterables	854
			Generator composition	855
			“yield” is a two-way street	857
			generator.throw	858
			generator.return	859
			Summary	860
			Tasks	860
			Recall iterables	865
			Async iterables	866
			Recall generators	867
			Async generators (finally)	868
			Real-life example: paginated data	870
			Summary	872
			What is a module?	878
			Core module features	879
			Browser-specific features	884
			Build tools	887
			Summary	887
			Export before declarations	891
			Export apart from declarations	891
			Import *	892
			Import “as”	892
			Export “as”	893
			Export default	893
			Re-export	896
			Summary	898
			The import() expression	903
			Proxy	910
			Default value with “get” trap	912
			Validation with “set” trap	913
			Iteration with “ownKeys” and “getOwnPropertyDescriptor”	914
			Protected properties with “deleteProperty” and other traps	916
			“In range” with “has” trap	918
			Wrapping functions: "apply"	919
			Reflect	920
			Proxy limitations	923
			Revocable proxies	926
			References	927
			Summary	927
			Tasks	928
			Using “eval”	938
			Summary	938
			Tasks	939
			Currying? What for?	943
			Advanced curry implementation	944
			Summary	945
			Reference type explained	951
			Summary	952
			Tasks	953
			Math operators	956
			Comparisons	957
			Boolean operations	957
			Polyfills	957
			References	958
			Surrogate pairs	963
			Diacritical marks and normalization	965
			DOM (Document Object Model)	970
			BOM (Browser Object Model)	970
			Summary	971
			An example of the DOM	974
			Autocorrection	976
			Other node types	977
			See it for yourself	978
			Interaction with console	980
			Summary	981
			On top: documentElement and body	985
			Children: childNodes, firstChild, lastChild	986
			Siblings and the parent	988
			Element-only navigation	989
			More links: tables	990
			Summary	991
			Tasks	991
			document.getElementById or just id	998
			querySelectorAll	999
			querySelector	1000
			matches	1000
			closest	1000
			getElementsBy*	1001
			Live collections	1002
			Summary	1003
			Tasks	1004
			DOM node classes	1008
			The “nodeType” property	1010
			Tag: nodeName and tagName	1011
			innerHTML: the contents	1012
			outerHTML: full HTML of the element	1013
			nodeValue/data: text node content	1014
			textContent: pure text	1015
			The “hidden” property	1015
			More properties	1016
			Summary	1016
			Tasks	1017
			DOM properties	1023
			HTML attributes	1024
			Property-attribute synchronization	1025
			DOM properties are typed	1026
			Non-standard attributes, dataset	1027
			Summary	1029
			Tasks	1030
			Example: show a message	1036
			Creating an element	1036
			Insertion methods	1037
			insertAdjacentHTML/Text/Element	1039
			Node removal	1040
			Cloning nodes: cloneNode	1041
			DocumentFragment	1042
			Old-school insert/remove methods	1043
			A word about “document.write”	1044
			Summary	1045
			Tasks	1046
			className and classList	1061
			Element style	1062
			Resetting the style property	1063
			Mind the units	1064
			Computed styles: getComputedStyle	1064
			Summary	1066
			Tasks	1067
			Sample element	1072
			Geometry	1073
			offsetParent, offsetLeft/Top	1074
			offsetWidth/Height	1075
			clientTop/Left	1076
			clientWidth/Height	1077
			scrollWidth/Height	1078
			scrollLeft/scrollTop	1079
			Don’t take width/height from CSS	1080
			Summary	1081
			Tasks	1082
			Width/height of the window	1087
			Width/height of the document	1088
			Get the current scroll	1088
			Scrolling: scrollTo, scrollBy, scrollIntoView	1088
			scrollIntoView	1089
			Forbid the scrolling	1089
			Summary	1090
			Element coordinates: getBoundingClientRect	1093
			elementFromPoint(x, y)	1096
			Using for “fixed” positioning	1096
			Document coordinates	1097
			Summary	1098
			Tasks	1098
			Event handlers	1110
			Accessing the element: this	1112
			Possible mistakes	1112
			addEventListener	1113
			Event object	1116
			Object handlers: handleEvent	1117
			Summary	1118
			Tasks	1119
			Bubbling	1126
			event.target	1127
			Stopping bubbling	1129
			Capturing	1129
			Summary	1132
			Delegation example: actions in markup	1139
			The “behavior” pattern	1140
			Summary	1142
			Tasks	1142
			Preventing browser actions	1151
			The “passive” handler option	1152
			event.defaultPrevented	1153
			Summary	1155
			Tasks	1156
			Event constructor	1165
			dispatchEvent	1165
			Bubbling example	1166
			MouseEvent, KeyboardEvent and others	1166
			Custom events	1167
			event.preventDefault()	1168
			Events-in-events are synchronous	1169
			Summary	1170
			Mouse event types	1175
			Events order	1175
			Mouse button	1176
			Modifiers: shift, alt, ctrl and meta	1176
			Coordinates: clientX/Y, pageX/Y	1177
			Preventing selection on mousedown	1178
			Summary	1179
			Tasks	1179
			Events mouseover/mouseout, relatedTarget	1186
			Skipping elements	1188
			Mouseout when leaving for a child	1190
			Events mouseenter and mouseleave	1193
			Event delegation	1195
			Summary	1201
			Tasks	1201
			Drag’n’Drop algorithm	1210
			Correct positioning	1212
			Potential drop targets (droppables)	1213
			Summary	1216
			Tasks	1217
			The brief history	1222
			Pointer event types	1222
			Pointer event properties	1223
			Multi-touch	1223
			Event: pointercancel	1224
			Pointer capturing	1225
			Summary	1227
			Teststand	1231
			Keydown and keyup	1233
			Auto-repeat	1235
			Default actions	1235
			Legacy	1236
			Mobile Keyboards	1236
			Summary	1237
			Tasks	1237
			Prevent scrolling	1242
			Tasks	1242
			Navigation: form and elements	1250
			Backreference: element.form	1252
			Form elements	1253
			References	1255
			Summary	1255
			Tasks	1256
			Events focus/blur	1259
			Methods focus/blur	1260
			Allow focusing on any element: tabindex	1261
			Delegation: focusin/focusout	1262
			Summary	1263
			Tasks	1263
			Event: change	1272
			Event: input	1272
			Events: cut, copy, paste	1273
			Summary	1274
			Tasks	1274
			Event: submit	1279
			Method: submit	1280
			Tasks	1280
			DOMContentLoaded	1285
			window.onload	1287
			window.onunload	1287
			window.onbeforeunload	1288
			readyState	1289
			Summary	1291
			defer	1296
			async	1298
			Dynamic scripts	1299
			Summary	1299
			Loading a script	1304
			Other resources	1305
			Crossorigin policy	1306
			Summary	1307
			Tasks	1308
			Syntax	1313
			Usage for integration	1314
			Usage for architecture	1315
			Additional methods	1317
			Summary	1318
			Range	1323
			Range properties	1326
			Range selection methods	1327
			Range editing methods	1327
			Selection	1329
			Selection properties	1330
			Selection events	1330
			Selection methods	1332
			Selection in form controls	1333
			Making unselectable	1336
			References	1337
			Summary	1337
			Event Loop	1341
			Use-case 1: splitting CPU-hungry tasks	1342
			Use case 2: progress indication	1344
			Use case 3: doing something after the event	1345
			Macrotasks and Microtasks	1345
			Summary	1347
			Tasks	1347
			Popup blocking	1354
			window.open	1354
			Example: a minimalistic window	1355
			Accessing popup from window	1356
			Accessing window from popup	1356
			Closing a popup	1357
			Moving and resizing	1357
			Scrolling a window	1358
			Focus/blur on a window	1358
			Summary	1358
			Same Origin	1363
			Windows on subdomains: document.domain	1364
			Iframe: wrong document pitfall	1365
			Collection: window.frames	1366
			The “sandbox” iframe attribute	1367
			Cross-window messaging	1368
			Summary	1370
			The idea	1375
			The demo	1375
			Old-school defences (weak)	1377
			X-Frame-Options	1379
			Showing with disabled functionality	1379
			Samesite cookie attribute	1381
			Summary	1381
			TypedArray	1386
			TypedArray methods	1389
			DataView	1389
			Summary	1390
			Tasks	1391
			TextEncoder	1397
			Blob as URL	1401
			Blob to base64	1402
			Image to blob	1403
			From Blob to ArrayBuffer	1404
			From Blob to stream	1404
			Summary	1404
			FileReader	1409
			Summary	1411
			Response headers	1420
			Request headers	1420
			POST requests	1421
			Sending an image	1422
			Summary	1423
			Tasks	1424
			Sending a simple form	1428
			FormData Methods	1428
			Sending a form with a file	1429
			Sending a form with Blob data	1430
			Summary	1431
			The AbortController object	1442
			Using with fetch	1443
			AbortController is scalable	1443
			Summary	1444
			Why is CORS needed? A brief history	1446
			Safe requests	1448
			CORS for safe requests	1448
			Response headers	1449
			“Unsafe” requests	1450
			Credentials	1453
			Summary	1454
			Tasks	1454
			referrer, referrerPolicy	1459
			mode	1461
			credentials	1461
			cache	1461
			redirect	1462
			integrity	1462
			keepalive	1462
			Creating a URL	1466
			SearchParams “?…”	1467
			Encoding	1468
			The basics	1474
			Response Type	1476
			Ready states	1477
			Aborting request	1478
			Synchronous requests	1478
			HTTP-headers	1478
			POST, FormData	1480
			Upload progress	1481
			Cross-origin requests	1482
			Summary	1482
			Not-so-useful progress event	1486
			Algorithm	1486
			Regular Polling	1490
			Long polling	1490
			Demo: a chat	1491
			Area of usage	1494
			A simple example	1500
			Opening a websocket	1501
			Data transfer	1503
			Rate limiting	1504
			Connection close	1504
			Connection state	1505
			Chat example	1505
			Summary	1507
			Getting messages	1511
			Reconnection	1512
			Message id	1513
			Connection status: readyState	1513
			Event types	1514
			Full example	1514
			Summary	1515
			Reading from document.cookie	1520
			Writing to document.cookie	1520
			path	1521
			domain	1521
			expires, max-age	1522
			secure	1523
			samesite	1523
			httpOnly	1525
			Appendix: Cookie functions	1525
			Appendix: Third-party cookies	1526
			Appendix: GDPR	1528
			Summary	1528
			localStorage demo	1532
			Object-like access	1533
			Looping over keys	1533
			Strings only	1534
			sessionStorage	1534
			Storage event	1535
			Summary	1536
			Tasks	1536
			Open database	1540
			Object store	1543
			Transactions	1545
			Transactions’ autocommit	1546
			Error handling	1548
			Searching	1549
			Deleting from store	1552
			Cursors	1552
			Promise wrapper	1554
			Summary	1555
			Control points	1561
			De Casteljau’s algorithm	1563
			Maths	1567
			Summary	1568
			CSS transitions	1573
			transition-property	1574
			transition-duration	1574
			transition-delay	1574
			transition-timing-function	1577
			Event: “transitionend”	1586
			Keyframes	1587
			Performance	1588
			Summary	1590
			Tasks	1590
			Using setInterval	1597
			Using requestAnimationFrame	1598
			Structured animation	1599
			Timing functions	1601
			Reversal: ease*	1604
			More interesting “draw”	1608
			Summary	1609
			Tasks	1610
			What’s common between…	1615
			Component architecture	1616
			Example: “time-formatted”	1620
			Observing attributes	1621
			Rendering order	1622
			Customized built-in elements	1624
			References	1625
			Summary	1625
			Tasks	1626
			Built-in shadow DOM	1631
			Shadow tree	1631
			Encapsulation	1633
			References	1633
			Summary	1633
			Inserting template	1637
			Summary	1638
			Named slots	1640
			Slot fallback content	1643
			Default slot: first unnamed	1643
			Menu example	1644
			Updating slots	1646
			Slot API	1647
			Summary	1648
			:host	1651
			Cascading	1651
			:host(selector)	1652
			Styling slotted content	1653
			CSS hooks with custom properties	1655
			Summary	1656
			Bubbling, event.composedPath()	1659
			event.composed	1660
			Custom events	1660
			Summary	1661
			Regular Expressions	1665
			Flags	1665
			Searching: str.match	1666
			Replacing: str.replace	1667
			Testing: regexp.test	1668
			Summary	1668
			Inverse classes	1672
			A dot is “any character”	1672
			Summary	1674
			Unicode properties \p{…}	1676
			Summary	1679
			Testing for a full match	1682
			Tasks	1683
			Searching at line start ^	1686
			Searching at line end $	1686
			Searching for \n instead of ^ $	1687
			Tasks	1691
			Escaping	1694
			A slash	1694
			new RegExp	1695
			Summary	1695
			Sets	1697
			Ranges	1697
			Excluding ranges	1698
			Escaping in […]	1699
			Ranges and flag “u”	1699
			Tasks	1700
			Quantity {n}	1703
			Shorthands	1703
			More examples	1704
			Tasks	1705
			Greedy search	1707
			Lazy mode	1709
			Alternative approach	1711
			Summary	1713
			Tasks	1714
			Examples	1718
			Parentheses contents in the match	1719
			Searching for all matches with groups: matchAll	1721
			Named groups	1722
			Capturing groups in replacement	1723
			Non-capturing groups with ?:	1724
			Summary	1724
			Tasks	1724
			Backreference by number: \N	1730
			Backreference by name: \k<name>	1731
			Example: regexp for time	1733
			Tasks	1734
			Lookahead	1739
			Negative lookahead	1739
			Lookbehind	1740
			Capturing groups	1740
			Summary	1741
			Tasks	1741
			Example	1745
			Simplified example	1745
			Back to words and strings	1747
			How to fix?	1748
			Preventing backtracking	1749
			str.match(regexp)	1756
			str.matchAll(regexp)	1757
			str.split(regexp|substr, limit)	1757
			str.search(regexp)	1758
			str.replace(str|regexp, str|func)	1758
			str.replaceAll(str|regexp, str|func)	1760
			regexp.exec(str)	1760
			regexp.test(str)	1761