2nd/10_Wiki/Topic_JavaScript/JavaScript_Set_Logic.md

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id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
javascript-set-logic	JavaScript Set Logic	Frontend	draft	conceptual		Set logic union intersection difference symmetricDifference isSubsetOf isDisjointFrom		B	0.88	2026-06-23	2026-06-23			javascript js web frontend w3schools set set-logic	https://www.w3schools.com/js/js_set_logic.asp

JavaScript Set Logic

🎯 한 줄 통찰 (One-line insight)

JavaScript 2025 added seven set-theory methods to Set — union, intersection, difference, symmetricDifference (returning new Sets) and isSubsetOf, isSupersetOf, isDisjointFrom (returning booleans) — for direct mathematical set operations. [S1]

🧠 핵심 개념 (Core concepts)

• Seven logical Set methods were added to the Set object in JavaScript 2025. [S1]
• Combining methods return a new Set — union, intersection, difference, symmetricDifference. [S1]
• Relationship methods return a boolean — isSubsetOf, isSupersetOf, isDisjointFrom. [S1]
• Each operates on this Set and an argument Set — e.g. A.union(B). [S1]
• Browser support is recent — Chrome/Edge 136 (Apr 2025), Firefox 129 (Aug 2024), Safari 18.2 (Dec 2024), Opera 120 (May 2025). [S1]

🧩 추출된 패턴 (Extracted patterns)

• Binary set operation — call a method on set A passing set B: const C = A.intersection(B);. [S1]
• New-Set vs predicate — combining ops yield a Set you store; relationship ops yield a true/false you store in answer. [S1]

📖 세부 내용 (Details)

union() — returns a new set containing the elements which are in this set, or in the argument set, or in both: [S1]

const A = new Set(['a','b','c']);
const B = new Set(['b','c','d']);

const C = A.union(B);

intersection() — returns a new set containing the elements which are in this set and in the argument set: [S1]

const A = new Set(['a','b','c']);
const B = new Set(['b','c','d']);

const C = A.intersection(B);

difference() — returns a new set containing elements which are in this set but not in the argument set: [S1]

const A = new Set(['a','b','c']);
const B = new Set(['b','c','d']);

const C = A.difference(B);

symmetricDifference() — returns a new set containing elements which are in this set or in the argument set, but not in both: [S1]

const A = new Set(['a','b','c']);
const B = new Set(['b','c','d']);

const C = A.symmetricDifference(B);

isSubsetOf() — returns true if all elements in this set is also elements in the argument set: [S1]

const A = new Set(['a','b','c']);
const B = new Set(['b','c','d']);

let answer = A.isSubsetOf(B);

isSupersetOf() — returns true if all elements in the argument set are also in this set: [S1]

const A = new Set(['a','b','c']);
const B = new Set(['b','c','d']);

let answer = A.isSupersetOf(B);

isDisjointFrom() — returns true if this set has no elements in common with the argument set: [S1]

const A = new Set(['a','b','c']);
const B = new Set(['b','c','d']);

let answer = A.isDisjointFrom(B);

Browser Support — JavaScript Set Logic methods are supported in modern browsers from 2024-2025: [S1]

Browser	Version	Release
Chrome	136	Apr 2025
Edge	136	Apr 2025
Firefox	129	Aug 2024
Safari	18.2	Dec 2024
Opera	120	May 2025

🛠️ 적용 사례 (Applied in summary)

The page's own snippets are the canonical applied examples — running each operation over two fixed Sets A = {a,b,c} and B = {b,c,d}, storing combining results in C and relationship results in answer. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Intersection of two Sets (language: JavaScript):

const C = A.intersection(B);

Subset predicate:

let answer = A.isSubsetOf(B);

⚖️ 비교 및 선택 기준 (Comparison & decision criteria)

Choose the method by the question being asked, per the source definitions: [S1]

• Need everything from both → union().
• Need only shared elements → intersection().
• Need this set minus the other → difference().
• Need elements unique to one side (the XOR) → symmetricDifference().
• Just need a yes/no relationship → isSubsetOf(), isSupersetOf(), or isDisjointFrom() (boolean, no new Set produced).

⚖️ 모순 및 업데이트 (Contradictions & updates)

These are new additions (JavaScript 2025). Older runtimes predating the browser versions listed will not have them. No contradictions found in the source. [S1]

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual (실제 적용 사례 발견 시 applied/validated로 승격 가능)
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.88
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: JavaScript Tutorial
• 관련 개념: JavaScript Sets, JavaScript Set Methods, JavaScript Maps
• 참조 맥락: Referenced when performing mathematical set operations between two Sets.

📚 출처 (Sources)

• [S1] W3Schools — JavaScript Set Logic — https://www.w3schools.com/js/js_set_logic.asp

📝 변경 이력 (Change history)

• 2026-06-23: Initial draft synthesized from the W3Schools "JavaScript Set Logic" page (Astra wiki-curation, P-Reinforce v3.1 format).