2nd/10_Wiki/Dev/Topic_CPP/CPP_Errors.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
cpp-errors	C++ Errors	Programming_Language	draft	conceptual		compile-time vs runtime errors dangling pointer C++ 에러		B	0.85	2026-07-04	2026-07-04			cpp programming-language w3schools errors	https://www.w3schools.com/cpp/cpp_errors.asp

CPP Errors

🎯 한 줄 통찰 (One-line insight)

The three runtime error examples (divide-by-zero, out-of-bounds array access, using DELETED memory via a dangling pointer) all share the same trait as C's equivalent chapter — none are caught at compile time, all three compile cleanly and only misbehave when actually executed — but C++'s third example specifically involves new/delete (int* ptr = new int(10); delete ptr; cout << *ptr;), a "dangling pointer" scenario that has no direct C equivalent since C's version used plain malloc/free. [S1]

🧠 핵심 개념 (Core concepts)

• Compile-time errors — prevent compilation entirely; e.g. missing semicolon, undeclared variable, type mismatch (invalid conversion from 'const char*' to 'int'). [S1]
• Runtime errors — the program compiles but crashes/misbehaves when RUN; e.g. division by zero, out-of-bounds array access, dangling pointer (reading memory after delete). [S1]
• Dangling pointer — a pointer that still holds an address after that memory was deleted; dereferencing it (*ptr) is invalid, C++-specific terminology tied to new/delete. [S1]
• Good habits — initialize variables, use meaningful names, keep indentation clean, keep functions short/focused, verify loop/condition behavior, read error messages carefully. [S1]

📖 세부 내용 (Details)

• Type mismatch error message (more specific than C's generic phrasing): int x = "Hello"; // error: invalid conversion from 'const char*' to 'int'. [S1]
• Dangling pointer, a C++-specific runtime error: int* ptr = new int(10); delete ptr; cout << *ptr; // invalid — dereferencing freed memory. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• 댕글링 포인터는 new/delete와 결합된 C++ 특유의 표현: C의 use-after-free 예제가 malloc/free 기반이었다면, C++에서는 new/delete와 결합된 "댕글링 포인터"라는 구체적 용어로 동일한 문제가 재확인됨. [S1]

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — 컴파일 타임 에러 3종과 런타임 에러 3종을 나란히 대비시킨 것이 두 에러 범주의 근본적 차이를 이해하는 실전 학습 자료로 활용된다. [S1]

💻 코드 패턴 (Code patterns)

Using memory after it's been deleted — a dangling pointer, compiles fine but is invalid at runtime (C++):

int* ptr = new int(10);
delete ptr;
cout << *ptr;  // invalid — dangling pointer

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.85
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: C++ Tutorial
• 관련 개념: CPP Date, CPP Memory Management New, CPP Exceptions
• 참조 맥락: 에러 섹션 첫 챕터 — 예외 처리(Exceptions) 챕터로 이어짐.

📚 출처 (Sources)

• [S1] W3Schools — C++ Errors — https://www.w3schools.com/cpp/cpp_errors.asp

📝 변경 이력 (Change history)

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