---
id: csharp-inheritance
title: "C# Inheritance"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["derived base class C#", "sealed keyword C#", "C# 상속"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.84
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["csharp", "programming-language", "w3schools", "oop", "inheritance"]
raw_sources: ["https://www.w3schools.com/cs/cs_inheritance.php"]
applied_in: []
github_commit: ""
---

# [[CSharp Inheritance]]

## 🎯 한 줄 통찰 (One-line insight)
C#'s inheritance syntax `class Car : Vehicle` OMITS the access specifier that C++'s equivalent `class Car : public Vehicle` REQUIRES — C# never lets you write `class Car : private Vehicle`, because member-level access (public/private/protected on each field/method) is the only lever C# offers, unlike C++ which layers an ADDITIONAL access specifier onto the inheritance relationship itself; and where C++ uses `final` to block further subclassing, C# uses a differently-named but functionally identical `sealed` keyword. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Derived class (child)** — the class that inherits from another class. [S1]
- **Base class (parent)** — the class being inherited from. [S1]
- **`:` syntax** — `class Car : Vehicle` — no access specifier before the base class name, unlike C++'s `class Car : public Vehicle`. [S1]
- **Inherited members** — a derived class gains ALL fields and methods from its base class, callable/accessible directly on the derived class's own objects. [S1]
- **Motivation** — code reusability: reuse an existing class's fields/methods instead of rewriting them in the new class. [S1]
- **`sealed` keyword** — prevents a class from being inherited at all; attempting to derive from a sealed class is a compile error (`'Car': cannot derive from sealed type 'Vehicle'`). [S1]

## 📖 세부 내용 (Details)
- Full example: `class Vehicle { public string brand = "Ford"; public void honk() { Console.WriteLine("Tuut, tuut!"); } } class Car : Vehicle { public string modelName = "Mustang"; } ... Car myCar = new Car(); myCar.honk(); Console.WriteLine(myCar.brand + " " + myCar.modelName);` → calls the PARENT's `honk()` and reads the PARENT's `brand` field directly on a `Car` object, alongside `Car`'s own `modelName`. [S1]
- Sealed class blocking inheritance: `sealed class Vehicle { ... } class Car : Vehicle { ... }` → compile error. [S1]
- The tutorial explicitly points forward to Polymorphism as building on inherited methods to perform different tasks. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **상속 문법에 접근 지정자가 없음**: C++는 `class Car : public Vehicle`처럼 상속 관계 자체에 public/private/protected 접근 지정자를 붙여야 했지만, C#은 `class Car : Vehicle`처럼 이 지정자 없이 상속하며, 접근 제어는 오직 멤버 단위(각 필드/메서드의 public/private/protected)로만 이뤄진다는 점이 확인됨. [S1]
- **final 대신 sealed라는 다른 이름의 동일 개념**: C++11의 `final` 키워드와 동일한 역할(더 이상 상속 불가)을 C#은 `sealed`라는 이름으로 제공한다는 점이 확인됨 — 개념은 같지만 키워드가 다름. [S1]
- **원문 구조상 상속이 단일 챕터로 압축됨**: Topic_CPP는 Inheritance/Access/Multilevel/Multiple을 4개 문서로 나눴지만, C# 사이드바는 cs_inheritance.php 단 하나로 기본 상속과 sealed를 모두 다룬다는 점이 확인됨 — 다단계·다중 상속에 대한 별도 챕터가 C# 튜토리얼에는 없음. [S1]

## 🛠️ 적용 사례 (Applied in summary)
Vehicle(부모)의 brand 필드와 honk() 메서드를 Car(자식)가 상속받아 Car 객체에서 그대로 사용하는 예제가 원문에서 직접 실전 활용 사례로 제시됨. [S1]

## 💻 코드 패턴 (Code patterns)
Inheritance without an access specifier on the base class (C#):
```csharp
class Vehicle
{
    public string brand = "Ford";
    public void honk()
    {
        Console.WriteLine("Tuut, tuut!");
    }
}
class Car : Vehicle   // no `public`/`private` before Vehicle, unlike C++
{
    public string modelName = "Mustang";
}

Car myCar = new Car();
myCar.honk();                                        // inherited method
Console.WriteLine(myCar.brand + " " + myCar.modelName); // inherited field + own field
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.84
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[C# Tutorial]]
- **관련 개념:** [[CSharp Properties]], [[CSharp Polymorphism]], [[CPP Inheritance]]
- **참조 맥락:** Inheritance 섹션의 유일 챕터 — Polymorphism & Abstract 섹션으로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — C# Inheritance — https://www.w3schools.com/cs/cs_inheritance.php

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