2nd/10_Wiki/Topic_Programming/Topic_C/C_Structs_Pointers.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-structs-pointers	C Structs and Pointers	Programming_Language	draft	conceptual		arrow operator struct pointer C 구조체 포인터		B	0.86	2026-07-04	2026-07-04			c programming-language w3schools structs pointers	https://www.w3schools.com/c/c_structs_pointers.php

C Structs and Pointers

🎯 한 줄 통찰 (One-line insight)

Passing a struct pointer into a function is the difference between the function seeing a temporary COPY versus the ORIGINAL — the updateYear() example modifies c->year inside the function and the change is visible back in main() afterward, specifically because a pointer (address) was passed rather than the struct itself, which would have been copied and discarded when the function returned. [S1]

🧠 핵심 개념 (Core concepts)

• struct Type *ptr — declares a pointer to a struct, same * syntax as any other pointer type. [S1]
• -> (arrow operator) — REPLACES the dot syntax when accessing members through a pointer; ptr->member is required instead of ptr.member. [S1]
• Function mutation via pointer — passing &myCar (the struct's address) lets a function permanently modify the original struct's members, unlike passing the struct by value. [S1]
• Three motivations for struct pointers — avoid copying large structs (performance/memory), allow functions to modify the original values, and enable dynamic struct creation via malloc() (previewed, covered later in Memory Management). [S1]

📖 세부 내용 (Details)

• Basic pointer declaration and arrow-operator access: struct Car car = {"Toyota", 2020}; struct Car *ptr = &car; printf("Brand: %s\n", ptr->brand); printf("Year: %d\n", ptr->year);. [S1]
• Function that mutates the original struct via a pointer parameter: void updateYear(struct Car *c) { c->year = 2025; } int main() { struct Car myCar = {"Toyota", 2020}; updateYear(&myCar); printf("Year: %d\n", myCar.year); } — prints 2025, not 2020, because the function received the original struct's address. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• 포인터 접근에는 화살표 연산자 필수: 구조체 변수는 점(.) 문법을 쓰지만, 포인터를 통한 접근은 반드시 화살표(->) 연산자를 써야 한다는 점이 문법적 차이로 명시됨. [S1]

🛠️ 적용 사례 (Applied in summary)

자동차 구조체의 연식(year)을 함수 안에서 포인터를 통해 2025로 변경하고 그 변경이 main()에도 반영되는 예제가 원문에서 직접 실전 활용 사례로 제시됨. [S1]

💻 코드 패턴 (Code patterns)

A function permanently modifying the original struct's field via a pointer parameter (C):

struct Car {
  char brand[30];
  int year;
};
void updateYear(struct Car *c) {
  c->year = 2025; // Change the year
}
int main() {
  struct Car myCar = {"Toyota", 2020};
  updateYear(&myCar); // Pass a pointer so the function can change the year
  printf("Year: %d\n", myCar.year); // 2025
  return 0;
}

✅ 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 Padding, C Pointers, C Enums
• 참조 맥락: 구조체와 포인터 — 열거형(Enums) 챕터로 이어짐, 포인터(Pointers) 챕터와 직접 연결.

📚 출처 (Sources)

• [S1] W3Schools — C Structs and Pointers — https://www.w3schools.com/c/c_structs_pointers.php

📝 변경 이력 (Change history)

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