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  1. Glossary
  2. Boolean
  3. Boolean (JavaScript)
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In this article

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

In this article

  • See also

Boolean (JavaScript)

A Boolean in JavaScript is a primitive value that can be either true or false.

A Boolean object is a wrapper around a Boolean primitive.

See also

  • The JavaScript global object
  • JavaScript data types and data structures

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