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최상위 10_Wiki/Topic_*였던 4개 카테고리 폴더를 10_Wiki/Topics/Topic_* 로 재배치. 콘텐츠 변경 없음(순수 폴더 이동) — Topics/ 하위 나머지 폴더는 이미 지난 커밋에서 전부 정리된 상태(잔존 항목은 에이전트 운영 상태 및 사용자가 보존을 요청한 업데이트0615/무제 3.canvas 뿐).
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+---
+id: java-inheritance
+title: "Java Inheritance"
+category: "Programming_Language"
+status: "draft"
+verification_status: "conceptual"
+canonical_id: ""
+aliases: ["subclass", "superclass", "extends keyword", "자바 상속"]
+duplicate_of: ""
+source_trust_level: "B"
+confidence_score: 0.9
+created_at: 2026-07-04
+updated_at: 2026-07-04
+review_reason: ""
+merge_history: []
+tags: ["java", "programming", "w3schools", "oop", "inheritance"]
+raw_sources: ["https://www.w3schools.com/java/java_inheritance.asp"]
+applied_in: []
+github_commit: ""
+---
+
+# [[Java Inheritance]]
+
+## 🎯 한 줄 통찰 (One-line insight)
+The choice between `protected` and `private` on a parent attribute directly determines whether inheritance "works" for that field — the source deliberately uses `protected` on Vehicle's `brand` and notes that `private` would have blocked Car from accessing it at all. [S1]
+
+## 🧠 핵심 개념 (Core concepts)
+- **Subclass (child)** — the class that inherits from another. [S1]
+- **Superclass (parent)** — the class being inherited from. [S1]
+- **`extends`** — keyword used to inherit from a class. [S1]
+- **`protected`** — required (not `private`) if a subclass needs to access a parent attribute directly. [S1]
+- **`final` on a class** — prevents any class from extending it; attempting to do so is a compile error. [S1]
+- **Motivation** — code reusability: inherit attributes/methods of an existing class into a new one. [S1]
+
+## 📖 세부 내용 (Details)
+- Basic inheritance: `class Vehicle { protected String brand = "Ford"; public void honk() { System.out.println("Tuut, tuut!"); } } class Car extends Vehicle { private String modelName = "Mustang"; ... } ... myCar.honk(); myCar.brand + " " + myCar.modelName;`. [S1]
+- Final class blocks inheritance: `final class Vehicle { ... } class Car extends Vehicle { ... } // error: cannot inherit from final Vehicle`. [S1]
+
+## ⚖️ 모순 및 업데이트 (Contradictions & updates)
+- **protected 필수성**: brand가 private이었다면 Car 클래스가 접근할 수 없었을 것이라는 점이 명시적으로 강조됨. [S1]
+
+## 🛠️ 적용 사례 (Applied in summary)
+현재 발견된 실제 적용 사례가 없습니다 — Vehicle→Car 상속 구조는 다형성(Polymorphism) 챕터의 직접적 전제가 된다. [S1]
+
+## 💻 코드 패턴 (Code patterns)
+Subclass inheriting a protected attribute and a method (Java):
+```java
+class Vehicle {
+    protected String brand = "Ford";
+    public void honk() {
+        System.out.println("Tuut, tuut!");
+    }
+}
+class Car extends Vehicle {
+    private String modelName = "Mustang";
+    public static void main(String[] args) {
+        Car myCar = new Car();
+        myCar.honk();
+        System.out.println(myCar.brand + " " + myCar.modelName);
+    }
+}
+```
+
+## ✅ 검증 상태 및 신뢰도
+- **상태:** draft
+- **검증 단계:** conceptual
+- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
+- **신뢰 점수:** 0.90
+- **중복 검사 결과:** 신규 생성 (New discovery)
+
+## 🔗 지식 그래프 (Knowledge Graph)
+- **상위/루트:** [[Java Tutorial]]
+- **관련 개념:** [[Java Modifiers]], [[Java Polymorphism]], [[Java Super Keyword]], [[Java Abstraction]]
+- **참조 맥락:** 클래스 간 속성/메서드 재사용 — 다형성/super 키워드 챕터로 직접 이어짐.
+
+## 📚 출처 (Sources)
+- [S1] W3Schools — Java Inheritance (Subclass and Superclass) — https://www.w3schools.com/java/java_inheritance.asp
+
+## 📝 변경 이력 (Change history)
+- 2026-07-04: Initial draft synthesized from the W3Schools "Java Inheritance" page (Astra wiki-curation, P-Reinforce v3.1 format).