2nd/10_Wiki/Topics/Domain_Programming/Topic_C/C_Enums.md

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

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
c-enums	C Enumeration (enum)	Programming_Language	draft	conceptual		enum keyword named constants C 열거형		B	0.86	2026-07-04	2026-07-04			c programming-language w3schools enums	https://www.w3schools.com/c/c_enums.php

C Enumeration (enum)

🎯 한 줄 통찰 (One-line insight)

Assigning an explicit value to just ONE enum item cascades forward — enum Level { LOW = 5, MEDIUM, HIGH }; gives MEDIUM the value 6 and HIGH the value 7 automatically, without being written explicitly — meaning enum numbering isn't independently assigned per item by default; each unlabeled item simply continues incrementing from whatever the PRECEDING item's value was. [S1]

🧠 핵심 개념 (Core concepts)

• enum — a type representing a group of named, unchangeable constants ("specifically listed" values). [S1]
• Default numbering — the first item is 0, the second 1, and so on, unless overridden. [S1]
• Forward-cascading custom values — setting one item's value shifts all SUBSEQUENT unlabeled items to continue counting up from it. [S1]
• Enum as an int under the hood — printing an enum variable with %d shows its underlying integer value, enabling direct use in switch statements matched against those integers. [S1]
• typedef with enum — eliminates needing to write enum before the type name every time a variable is declared, a pure readability/brevity improvement. [S1]

📖 세부 내용 (Details)

• Default numbering: enum Level { LOW, MEDIUM, HIGH }; enum Level myVar = MEDIUM; printf("%d", myVar); // 1. [S1]
• Fully custom values: enum Level { LOW = 25, MEDIUM = 50, HIGH = 75 };. [S1]
• Cascading from one custom value: enum Level { LOW = 5, MEDIUM, HIGH }; — MEDIUM becomes 6, HIGH becomes 7. [S1]
• Enum used in a switch: enum Level myVar = MEDIUM; switch (myVar) { case 1: ... case 2: ... case 3: ... } (matching against LOW=1, MEDIUM=2, HIGH=3). [S1]
• typedef shortcut: typedef enum {MON, TUE, WED, THU, FRI, SAT, SUN} Day; Day today = WED; instead of enum Day today = WED;. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• 하나의 값 지정이 이후 항목까지 연쇄적으로 영향: LOW = 5로 지정하면 뒤따르는 MEDIUM, HIGH는 명시하지 않아도 자동으로 6, 7이 된다는 점이 명확히 확인됨 — 각 항목이 독립적으로 0부터 재시작하는 것이 아님. [S1]

🛠️ 적용 사례 (Applied in summary)

요일(Day)이나 월과 같이 절대 변하지 않는 값 집합에 enum을 사용하는 것이 실전 활용의 대표 사례로 원문에 직접 제시됨. [S1]

💻 코드 패턴 (Code patterns)

Setting one enum value causes subsequent items to cascade forward from it (C):

enum Level {
  LOW = 5,
  MEDIUM, // Now 6
  HIGH    // Now 7
};

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.86
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: C Tutorial
• 관련 개념: C Structs Pointers, C Switch, C Unions, C Typedef
• 참조 맥락: 열거형 — 유니온(Unions) 챕터로 이어짐, typedef 챕터와 직접 연결.

📚 출처 (Sources)

• [S1] W3Schools — C Enumeration (enum) — https://www.w3schools.com/c/c_enums.php

📝 변경 이력 (Change history)

• 2026-07-04: Initial draft synthesized from the W3Schools "C Enumeration (enum)" page (Astra wiki-curation, P-Reinforce v3.1 format).