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  1. Glossary
    1. Abstração
    2. accent
    3. Acessibilidade
    4. Árvore de Acessibilidade
    5. Accessible description
    6. Accessible name
    7. Adobe Flash
    8. Advance measure
    9. AJAX
    10. Algoritmo
    11. Contêiner de Alinhamento
    12. Tópico de Alinhamento
    13. Alpha (canal alfa)
    14. ALPN
    15. API
    16. Apple Safari
    17. Application Context
    18. Argumento
    19. ARIA
    20. ARPA
    21. Arpanet
    22. Array
    23. ASCII
    24. Aspect ratio
    25. Assíncrono
    26. ATAG
    27. Atributo HTML
    28. Authentication
    29. Authenticator
    30. Bandwidth
    31. Base64
    32. Baseline
      1. Baseline (compatibility)
      2. Baseline (typography)
    33. BCP 47 language tag
    34. Beacon
    35. Bézier curve
    36. bfcache
    37. BiDi
    38. BigInt
    39. Binding
    40. Bitwise flags
    41. Blink
    42. blink element (<blink> tag)
    43. Block
      1. Bloco (CSS)
      2. Block (scripting)
    44. Block cipher mode of operation
    45. Elementos block-level
    46. Booleano
      1. Boolean (JavaScript)
      2. Boolean attribute (ARIA)
      3. Boolean attribute (HTML)
    47. Bounding Box
    48. Breadcrumb
    49. Brotli compression
    50. Navegador
    51. Browsing context
    52. Buffer
    53. Bun
    54. Cache
    55. Cacheable
    56. CalDAV
    57. Call stack (Pilha de chamadas)
    58. Função Callback
    59. Camel case
    60. Canonical order
    61. Canvas
    62. Card sorting
    63. CardDAV
    64. caret
    65. CDN
    66. Certificate authority
    67. Certified
    68. Challenge-response authentication
    69. Caractere
    70. Character encoding
    71. Character reference
    72. Character set
    73. Chrome
    74. CIA
    75. Cipher
    76. Cipher suite
    77. Ciphertext
    78. Class
    79. Client-side rendering (CSR)
    80. Closure
    81. Cloud
    82. Cloud computing
    83. CMS
    84. Code point
    85. Code splitting
    86. Code unit
    87. Codec
    88. Color space
    89. Color wheel
    90. Compile
    91. Compile time
    92. Composite operation
    93. Compression Dictionary Transport
    94. Programação de Computadores
    95. Conditional
    96. Constant
    97. Constructor
    98. Content header
    99. Continuous Media
    100. Control flow
    101. Cookie
    102. Copyleft
    103. CORS
    104. CORS-safelisted request header
    105. CORS-safelisted response header
    106. Crawler
    107. Credential
    108. CRLF
    109. Cross Axis
    110. Cross-site request forgery (CSRF)
    111. Cross-site scripting (XSS)
    112. CRUD
    113. Cryptanalysis
    114. Cryptography
    115. CSP
    116. CSS
    117. Modelo de Objeto CSS (CSSOM)
    118. Pixel CSS
    119. Pré-processador CSS
    120. Cumulative Layout Shift (CLS)
    121. Data structure
    122. Database
    123. Debounce
    124. Decryption
    125. Deep copy
    126. Delta
    127. Denial of Service (DoS)
    128. Deno
    129. Descriptor (CSS)
    130. Deserialization
    131. Developer Tools
    132. Device pixel
    133. Digital certificate
    134. Digital signature
    135. Distributed Denial of Service (DDoS)
    136. DMZ
    137. DNS
    138. Doctype
    139. Document directive
    140. Document environment
    141. DOM
    142. Domínio
    143. Nome de domínio
    144. Domain sharding
    145. Dominator
    146. DSL
      1. DSL (Digital Subscriber Line)
      2. DSL (Domain-Specific Language)
    147. DTLS (Datagram Transport Layer Security)
    148. DTMF (Dual-Tone Multi-Frequency signaling)
    149. Dynamic typing
    150. ECMA
    151. ECMAScript
    152. Effective connection type
    153. Elemento
    154. Encapsulation
    155. Encryption
    156. Endianness
    157. Engine
      1. JavaScript engine
      2. Rendering engine
    158. Entity
    159. Cabeçalho de entidade
    160. Enumerated
    161. Escape character
    162. eTLD
    163. Event
    164. Exception
    165. EXIF
    166. Expando
    167. Fallback alignment
    168. Falsy
    169. Favicon
    170. Federated identity
    171. Fetch directive
    172. Fetch metadata request header
    173. Fingerprinting
    174. Firefox OS
    175. Firewall
    176. First Contentful Paint (FCP)
    177. First CPU idle
    178. First Input Delay (FID) Deprecated
    179. First Meaningful Paint (FMP)
    180. First Paint (FP)
    181. Função First-class
    182. Flex
    183. Flex Container
    184. Flex Item
    185. Flexbox
    186. Flow relative values
    187. Nome de cabeçalho proibido
    188. Forbidden response header name
    189. Fork
    190. Fragmentainer
    191. Frame rate (FPS)
    192. FTP
    193. FTU
    194. Função
    195. Teste de Fuzzing
    196. Gamut
    197. Garbage collection
    198. Gecko
    199. Cabeçalho Genérico
    200. GIF
    201. Git
    202. Global object
    203. Global scope
    204. Global variable
    205. Glyph
    206. Google Chrome
    207. GPL
    208. GPU
    209. Degradação graciosa
    210. Grade
    211. Grid Areas
    212. Grid Axis
    213. Grid Cell
    214. Grid Column
    215. Grid container
    216. Grid Lines
    217. Grid Row
    218. Grid Tracks
    219. Guaranteed-invalid value
    220. Gutters
    221. gzip compression
    222. Hash function
    223. Head
    224. Head-of-line blocking
    225. High-level programming language
    226. HMAC
    227. Hoisting
    228. Host
    229. Hotlink
    230. Houdini
    231. HPKP
    232. HSTS
    233. HTML
    234. HTML color codes
    235. HTML5
    236. HTTP
    237. HTTP Content
    238. Cabeçalho HTTP
    239. HTTP/2
    240. HTTP/3
    241. HTTPS
    242. HTTPS RR
    243. Hyperlink
    244. Hypertext
    245. IANA
    246. ICANN
    247. ICE
    248. IDE
    249. Idempotente
    250. Identificador (Identifier)
    251. Identity provider (IdP)
    252. IDL
    253. IETF
    254. IIFE
    255. IMAP
    256. Immutable
    257. IndexedDB
    258. Information architecture
    259. Inheritance
    260. Ink overflow
    261. Elementos inline
    262. Input method editor
    263. Inset properties
    264. Instance
    265. Interaction to Next Paint (INP)
    266. Internationalization (i18n)
    267. Internet
    268. Interpolation
    269. Intrinsic size
    270. Endereço IP
    271. IPv4
    272. IPv6
    273. IRC
    274. ISO
    275. ISP
    276. ITU
    277. Jank
    278. Java
    279. JavaScript
    280. Jitter
    281. JPEG
    282. JSON
    283. JSON type representation
    284. Just-In-Time Compilation (JIT)
    285. Kebab case
    286. Key
    287. Palavra-chave
    288. Largest Contentful Paint (LCP)
    289. Latency
    290. Modelo de layout
    291. Layout viewport
    292. Lazy load
    293. Leading
    294. LGPL
    295. Ligature
    296. Literal
    297. Local scope
    298. Local variable
    299. Locale
    300. Localização
    301. Logical properties
    302. Long task
    303. Loop
    304. Lossless compression
    305. Lossy compression
    306. LTR (Left To Right)
    307. Main Axis
    308. Main thread
    309. marcação
    310. MathML
    311. Media
      1. Media (Audio-visual presentation)
      2. Media (CSS)
    312. Media query
    313. Metadata
    314. Method
    315. Microsoft Edge
    316. Microsoft Internet Explorer
    317. Middleware
    318. MIME
    319. MIME type
    320. Minification
    321. MitM
    322. Mixin
    323. Mobile First
    324. Modem
    325. Modularity
    326. Mozilla Firefox
    327. Mutável
    328. MVC
    329. Namespace
    330. NaN
    331. NAT
    332. Native
    333. Navigation directive
    334. Netscape Navigator
    335. Network throttling
    336. NNTP
    337. Node
      1. Node (DOM)
      2. Node (networking)
    338. Node.js
    339. Non-normative
    340. Normative
    341. Nulo
    342. Nullish value
    343. Number
    344. Objeto
    345. Object reference
    346. OOP
    347. OpenGL
    348. OpenSSL
    349. Navegador Opera
    350. Operand
    351. Operador
    352. Origem
    353. OTA
    354. OWASP
    355. P2P
    356. PAC
    357. Packet
    358. Page load time
    359. Page prediction
    360. Parameter
    361. Parent object
    362. Parse
    363. Parser
    364. Payload body
    365. Payload header
    366. PDF
    367. Perceived performance
    368. Percent-encoding
    369. PHP
    370. Physical properties
    371. Pixel
    372. Placeholder names
    373. Plaintext
    374. Plugin
    375. PNG
    376. Polyfill
    377. Polymorphism
    378. POP3
    379. Port
    380. Prefetch
    381. Requisição Preflight
    382. Prerender
    383. Presto
    384. Primitivo
    385. Privileged
    386. Privileged code
    387. Progressive Enhancement
    388. Progressive web apps
    389. Promise
    390. Propriedade
      1. Propriedade (CSS)
      2. Propriedade (JavaScript)
    391. Protocolo
    392. Prototype
    393. Prototype-based programming
    394. Proxy server
    395. Pseudo-class
    396. Pseudo-element
    397. Pseudocode
    398. Public-key cryptography
    399. Python
    400. Quality values
    401. Quaternion
    402. QUIC
    403. RAIL
    404. Random Number Generator
    405. Raster image
    406. Rate limit
    407. RDF
    408. Reading order
    409. Real User Monitoring (RUM)
    410. Recursão
    411. Reflow
    412. Expressão regular
    413. Relying party
    414. Render-blocking
    415. Repaint
    416. Replaced elements
    417. Replay attack
    418. Repo
    419. Reporting directive
    420. Representation header
    421. Cabeçalho de Requisição
    422. Resource Timing
    423. Response header
    424. Web Design Responsivo
    425. REST
    426. RGB
    427. RIL
    428. Robots.txt
    429. Round Trip Time (RTT)
    430. Router
    431. RSS
    432. Rsync
    433. RTCP (RTP Control Protocol)
    434. RTF
    435. RTL (Right to Left)
    436. RTP (Real-time Transport Protocol) and SRTP (Secure RTP)
    437. RTSP: Real-time streaming protocol
    438. Ruby
    439. Seguro
      1. Safe (HTTP Methods)
    440. Salt
    441. Same-origin policy
    442. SCM
    443. Escopo
    444. Screen reader
    445. Script-supporting element
    446. Scroll boundary
    447. Scroll chaining
    448. Scroll container
    449. Scroll snap
    450. SCTP
    451. SDK (Software Development Kit)
    452. SDP
    453. Search engine
    454. Secure Context
    455. SSL
    456. Selector (CSS)
    457. Semântica
    458. SEO - Otimização dos Mecanismos de Buscas
    459. Serializable object
    460. Serialization
    461. Servidor
    462. Server Timing
    463. Server-side rendering (SSR)
    464. Session Hijacking
    465. SGML
    466. Shadow tree
    467. Shallow copy
    468. Shim
    469. Signature
      1. Signature (functions)
      2. Signature (security)
    470. SIMD
    471. SISD
    472. Site
    473. Site map
    474. SLD
    475. Sloppy mode
    476. Slug
    477. Smoke Test
    478. SMPTE (Society of Motion Picture and Television Engineers)
    479. SMTP
    480. Snake case
    481. Snap positions
    482. SOAP
    483. Source map
    484. SPA (Single-page application)
    485. Specification
    486. Speculative parsing
    487. Speed index
    488. SQL
    489. SQL Injection
    490. SRI
    491. Stacking context
    492. State machine
    493. Declaração
    494. Static method
    495. Static site generator (SSG)
    496. Static typing
    497. Sticky activation
    498. Strict mode
    499. String
    500. Stringifier
    501. STUN
    502. Style origin
    503. Stylesheet
    504. Submit button
    505. SVG
    506. SVN
    507. Symbol
    508. Symmetric-key cryptography
    509. Síncrono
    510. Syntax
    511. Syntax error
    512. Synthetic monitoring
    513. Table grid box
    514. Table Wrapper Box
    515. Tag
    516. TCP
    517. TCP handshake
    518. TCP slow start
    519. Telnet
    520. Texel
    521. The Khronos Group
    522. Thread
    523. Three js
    524. Throttle
    525. Time to first byte
    526. Time to interactive
    527. TLD
    528. TOFU
    529. Top layer
    530. Transient activation
    531. TLS
    532. Tree shaking
    533. Trident
    534. Truthy
    535. TTL
    536. TURN
    537. Type
    538. Type coercion
    539. Conversão de Tipo
    540. TypeScript
    541. UAAG
    542. UDP (User Datagram Protocol)
    543. UI
    544. undefined
    545. Unicode
    546. Unix time
    547. URI
    548. URL
    549. URN
    550. Usenet
    551. User agent
    552. UTF-8
    553. UUID
    554. UX
    555. Validator
    556. Valor
    557. Variável
    558. Prefixos vendor
    559. Viewport
    560. Visual Viewport
    561. Void element
    562. VoIP
    563. W3C
    564. WAI
    565. WCAG
    566. Web performance
    567. Web server
    568. Web standards
    569. WebAssembly
    570. WebDAV
    571. WebExtensions
    572. WebGL
    573. WebIDL
    574. WebKit
    575. WebM
    576. WebP
    577. WebRTC
    578. WebSockets
    579. WebVTT
    580. WHATWG
    581. Whitespace
    582. WindowProxy
    583. World Wide Web
    584. Wrapper
    585. XForms Deprecated
    586. XHTML
    587. XInclude
    588. XLink
    589. XML
    590. XHR (XMLHttpRequest)
    591. XPath
    592. XQuery
    593. XSLT
    594. Zstandard compression

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undefined

Um valor primitive automaticamente atribuido para variaveis que foram recentemente declaradas ou para arguments formais para qual não existem argumentos atualmente.

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Conhecimentos gerais

  • Undefined value no Wikipedia

Referência Técnica

  • JavaScript data types and data structures

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