---
id: c-structs-nested
title: "C Nested Structures"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["struct inside struct", "layered data", "C 중첩 구조체"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.85
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["c", "programming-language", "w3schools", "structs", "nested-structs"]
raw_sources: ["https://www.w3schools.com/c/c_structs_nested.php"]
applied_in: []
github_commit: ""
---

# [[C Nested Structures]]

## 🎯 한 줄 통찰 (One-line insight)
Accessing a nested struct's member requires CHAINING dot syntax (`car1.owner.firstName`) rather than a single dot — each additional layer of nesting adds one more `.` hop, meaning the access path itself mirrors the data's logical hierarchy exactly (car → owner → firstName), making deeply nested structures self-documenting about their own structure just from how you reach a value. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Nested structure** — a struct that contains ANOTHER struct as one of its members, useful for grouping related data in layers. [S1]
- **Chained dot access** — reaching a nested member requires one `.` per layer of nesting (`car1.owner.firstName`, not a shortcut). [S1]
- **Composition over flattening** — instead of cramming an owner's first/last name directly into the `Car` struct, a separate `Owner` struct is composed INTO `Car`, keeping each struct focused on one concept. [S1]

## 📖 세부 내용 (Details)
- Defining and nesting: `struct Owner { char firstName[30]; char lastName[30]; }; struct Car { char brand[30]; int year; struct Owner owner; };`. [S1]
- Initializing a nested struct by passing an already-built inner struct as one field: `struct Owner person = {"John", "Doe"}; struct Car car1 = {"Toyota", 2010, person};`. [S1]
- Chained access to reach the innermost value: `printf("Owner: %s %s\n", car1.owner.firstName, car1.owner.lastName);`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- 현재까지 발견된 모순 사항 없음 (No contradictions found in available sources).

## 🛠️ 적용 사례 (Applied in summary)
자동차(Car) 구조체 안에 소유자(Owner) 구조체를 중첩시켜 자동차와 소유자 정보를 계층적으로 묶는 예제가 원문에서 직접 실전 활용 사례로 제시됨. [S1]

## 💻 코드 패턴 (Code patterns)
Chained dot-access to reach a value inside a nested struct (C):
```c
struct Owner {
  char firstName[30];
  char lastName[30];
};
struct Car {
  char brand[30];
  int year;
  struct Owner owner; // Nested structure
};
int main() {
  struct Owner person = {"John", "Doe"};
  struct Car car1 = {"Toyota", 2010, person};
  printf("Owner: %s %s\n", car1.owner.firstName, car1.owner.lastName);
  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:** 0.85
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[C Tutorial]]
- **관련 개념:** [[C Structs]], [[C Structs Padding]]
- **참조 맥락:** 중첩 구조체 — 구조체 정렬/패딩(Structs Padding) 챕터로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — C Nested Structures — https://www.w3schools.com/c/c_structs_nested.php

## 📝 변경 이력 (Change history)
- 2026-07-04: Initial draft synthesized from the W3Schools "C Nested Structures" page (Astra wiki-curation, P-Reinforce v3.1 format).
