2nd/10_Wiki/Dev/Topic_C/C_Arrays_Loop.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-arrays-loop	C Array Loop	Programming_Language	draft	conceptual		loop through array adaptive loop length C 배열 반복문		B	0.86	2026-07-04	2026-07-04			c programming-language w3schools arrays loops	https://www.w3schools.com/c/c_arrays_loop.php

C Array Loop

🎯 한 줄 통찰 (One-line insight)

A hardcoded loop bound (i < 4) silently breaks the moment the array's contents change size — the source explicitly flags this as "not ideal, since it will only work for arrays of a specified size" — while replacing it with sizeof(arr)/sizeof(arr[0]) makes the SAME loop automatically correct for an array of ANY length, turning a brittle magic number into a self-maintaining computation. [S1]

🧠 핵심 개념 (Core concepts)

• Hardcoded loop bound (fragile) — for (i = 0; i < 4; i++) only works correctly for exactly a 4-element array; adding/removing elements breaks it silently. [S1]
• sizeof formula-driven bound (robust) — int length = sizeof(arr) / sizeof(arr[0]); for (i = 0; i < length; i++) automatically adapts to the array's actual current size. [S1]
• Standing rule — the chapter's own summary: "Always use the sizeof formula when looping through arrays." [S1]

📖 세부 내용 (Details)

• Fragile hardcoded-bound loop: int myNumbers[] = {25, 50, 75, 100}; int i; for (i = 0; i < 4; i++) { printf("%d\n", myNumbers[i]); }. [S1]
• Robust size-adaptive loop: int myNumbers[] = {25, 50, 75, 100}; int length = sizeof(myNumbers) / sizeof(myNumbers[0]); int i; for (i = 0; i < length; i++) { printf("%d\n", myNumbers[i]); }. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• 하드코딩된 루프 경계의 취약성: 배열 원소 개수가 바뀌면 i < 4 같은 고정된 조건이 더 이상 맞지 않게 된다는 점이 "이상적이지 않다"고 명시적으로 지적되며, sizeof 공식을 항상 쓰라는 규칙으로 이어짐. [S1]

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — sizeof 기반 반복문이 이후 Arrays RealLife 챕터의 평균 계산·최솟값 찾기 예제에서 그대로 재사용된다. [S1]

💻 코드 패턴 (Code patterns)

A loop that automatically adapts to any array size using the sizeof formula (C):

int myNumbers[] = {25, 50, 75, 100};
int length = sizeof(myNumbers) / sizeof(myNumbers[0]);
int i;
for (i = 0; i < length; i++) {
  printf("%d\n", myNumbers[i]);
}

✅ 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 Arrays Size, C Arrays Multi, C Arrays RealLife
• 참조 맥락: 배열 반복문 — 다차원 배열(Arrays Multi) 챕터로 이어짐.

📚 출처 (Sources)

• [S1] W3Schools — C Array Loop — https://www.w3schools.com/c/c_arrays_loop.php

📝 변경 이력 (Change history)

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