2nd/10_Wiki/Topic_Programming/Topic_CPP/CPP_Inheritance_Access.md

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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-inheritance-access	C++ Inheritance Access	Programming_Language	draft	conceptual		protected access specifier C++ 상속과 protected		B	0.86	2026-07-04	2026-07-04			cpp programming-language w3schools oop inheritance protected	https://www.w3schools.com/cpp/cpp_inheritance_access.asp

CPP Inheritance Access

🎯 한 줄 통찰 (One-line insight)

This chapter reveals WHY protected exists as a third option distinct from private: a private attribute in the base class would be completely UNREACHABLE by the derived class's own methods, forcing awkward workarounds, while protected lets Programmer's setSalary()/getSalary() methods directly manipulate Employee's salary field as if it were their own — meaning protected specifically solves the "I need child classes to touch this, but nobody else" access pattern that neither public nor private alone can express. [S1]

🧠 핵심 개념 (Core concepts)

• protected — similar to private (inaccessible from OUTSIDE the class), but UNLIKE private, accessible from DERIVED (child) classes. [S1]
• Derived-class methods manipulating a protected base attribute — Programmer's setSalary()/getSalary() methods read/write Employee's protected int salary; directly, as if it belonged to Programmer. [S1]

📖 세부 내용 (Details)

• A protected base attribute manipulated by a derived class's own methods: class Employee { protected: int salary; }; class Programmer: public Employee { public: int bonus; void setSalary(int s) { salary = s; } int getSalary() { return salary; } }; Programmer myObj; myObj.setSalary(50000); myObj.bonus = 15000;. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• protected는 private과 public 사이의 중간 지점: 클래스 외부에서는 접근 불가하다는 점에서 private과 같지만, 파생 클래스에서는 접근 가능하다는 점에서 다르다는 것이 확인됨 — 이는 private만으로는 해결 못 하는 "자식 클래스만 접근 허용" 요구를 해결. [S1]

🛠️ 적용 사례 (Applied in summary)

Employee의 protected 급여(salary)를 Programmer 파생 클래스가 자체 getter/setter로 직접 다루는 예제가 protected의 대표 실전 활용 사례로 원문에 직접 제시됨. [S1]

💻 코드 패턴 (Code patterns)

A protected base attribute directly manipulated by a derived class's own methods (C++):

class Employee {
protected: // accessible in derived classes, not outside
  int salary;
};
class Programmer: public Employee {
public:
  int bonus;
  void setSalary(int s) { salary = s; }
  int getSalary() { return salary; }
};

✅ 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: CPP Inheritance, CPP Access Specifiers, CPP Inheritance Multilevel
• 참조 맥락: 상속과 protected — 다단계 상속(Inheritance Multilevel) 챕터로 이어짐.

📚 출처 (Sources)

• [S1] W3Schools — C++ Inheritance Access — https://www.w3schools.com/cpp/cpp_inheritance_access.asp

📝 변경 이력 (Change history)

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