Booleans - language feature

Example from JSON, JSON5, JSONiq, JSON with Comments, Superjson, Hocon, Jsonnet:

false

Example from Go:

c := true

Example from TypeScript, Static Typescript:

const result = true

Example from Nim:

let res = true

Example from Ion:

null.bool
true
false

Example from Slope:

(define open? #t)

Example from Jule:

true false

Example from Bel:

; The symbol nil represents falsity as well as the empty list.
; The symbol t is the default representation for truth, but any object other than nil also counts as true.

Example from opengraph:

true
false
1
0

Languages with Booleans include Java, JavaScript, C, Python, SQL, C++, PHP, C#, Ruby, MySQL, R, JSON, Go, COBOL, Scala, Swift, Ada, PostgreSQL, Rust, Kotlin, Pascal, Lua, TypeScript, Objective-C, Elixir, Visual Basic, Julia, Dart, Modula-2, Solidity, Reason, Crystal, CoffeeScript, F#, OCaml, Modula-3, Groovy, UML, GraphQL, Nim, Liquid, Visual Basic .NET, ANTLR, Lasso, Oz, Protocol Buffers, ABAP, Simula, PL/SQL, Nearley, idyll, MoonScript, BlitzBasic, Click, EDN, SPARQL, JSON5, F*, Cython, NetLogo, HCL, MariaDB, Isabelle, TLA, C3, S-algol, eC, wisp, Twig, Classroom Object Oriented Language, Transact-SQL, Bluespec, Ion, Augmented Backus-Naur Form, janet, Action!, progsbase, Slope, Jule, Angelscript, Pizza, Spin, Bel, Concise Encoding, blockml, Apex, JSONiq, ArkScript, carth, mckeeman-form, XL, Jupyter Notebook, JSON with Comments, C2, Cell, Caché Basic, Ezhil, spry, Superjson, Jison Lex, Arden syntax, llhd, PLZ, PROMAL, Hocon, PowerQuery M, Ren, Jsonnet, Ligo, JS++, Uniform eXchange Format, fizz, BALGOL, C/AL, JSON Lines, Mscgen, Sophia, opengraph, Amazon Redshift, Freefem, Deesel, Friendly Enough Expression Language, Tick C, cooC, Real-Time Concurrent C, ADLIB, Static Typescript, Extended Pascal, Modula-2+

Languages without Booleans include Markdown, SQLite, Ini, Marp