2nd/10_Wiki/Dev/Topic_CSharp/CSharp_Variables_Constants.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
csharp-variables-constants	C# Constants	Programming_Language	draft	conceptual		const keyword C# C# 상수		B	0.84	2026-07-04	2026-07-04			csharp programming-language w3schools constants	https://www.w3schools.com/cs/cs_variables_constants.php

CSharp Constants

🎯 한 줄 통찰 (One-line insight)

C#'s const keyword is placed BEFORE the type (const int myNum = 15;), exactly mirroring C's const int and C++'s identical placement — but C# adds a strictness neither predecessor enforces at the same chapter level: a const MUST be initialized at declaration, with no separate "declare now, assign later" escape hatch, producing a hard compiler error ("A const field requires a value to be provided") rather than the vaguer undefined/uninitialized-value risk C's const-without-init could silently create. [S1]

🧠 핵심 개념 (Core concepts)

• const keyword — placed before the variable type, makes the variable unchangeable and read-only after its initial assignment. [S1]
• Mandatory initialization — a const MUST be assigned a value at the point of declaration; declaring one without a value is a compile error. [S1]
• Use case — values that should never change, like PI (3.14159...), protecting code from accidental overwrites by the same or other developers. [S1]

📖 세부 내용 (Details)

• Declaration + illegal reassignment: const int myNum = 15; myNum = 20; // error. [S1]
• Explicit error message quoted from the compiler: "A const field requires a value to be provided" when a const is declared without a value. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• 초기화 없는 const 선언이 하드 에러로 즉시 차단됨: C의 const int x;는 선언 자체는 허용되고 이후 대입이 불가능해 초기화되지 않은 값이 남는 위험이 있었지만, C#은 초기화 없는 const 선언 자체를 컴파일 에러로 명시적으로 차단한다는 점이 이번 챕터에서 확인됨. [S1]

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — PI처럼 절대 변하지 않아야 하는 값의 예시로 const 사용이 원문에서 언급됨. [S1]

💻 코드 패턴 (Code patterns)

const requires initialization at declaration — no exceptions (C#):

const int myNum = 15;
myNum = 20; // error - cannot assign to a const variable

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.84
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: C# Tutorial
• 관련 개념: CSharp Variables Identifiers, CSharp Variables Display, C Constants
• 참조 맥락: Variables 섹션 — Display Variables 챕터로 이어짐.

📚 출처 (Sources)

• [S1] W3Schools — C# Constants — https://www.w3schools.com/cs/cs_variables_constants.php

📝 변경 이력 (Change history)

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