2nd/10_Wiki/Topic_Programming/Topic_CSharp/CSharp_Interface_Multi.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
csharp-interface-multi	C# Multiple Interfaces	Programming_Language	draft	conceptual		implement multiple interfaces C# C# 다중 인터페이스		B	0.83	2026-07-04	2026-07-04			csharp programming-language w3schools oop interface	https://www.w3schools.com/cs/cs_interface_multi.php

CSharp Interface Multi

🎯 한 줄 통찰 (One-line insight)

This short chapter delivers exactly the payoff the previous Interface chapter promised: a single class implementing MULTIPLE interfaces via a comma-separated list after : (class DemoClass : IFirstInterface, ISecondInterface) — this is as close as C# gets to C++'s multiple inheritance, but the constraint is real: every interface in the list contributes only bodyless method signatures, never actual field data or base implementation, so C# is achieving multiple "contracts" rather than C++'s multiple actual base-class STATE and behavior. [S1]

🧠 핵심 개념 (Core concepts)

• Comma-separated interface list — class DemoClass : IFirstInterface, ISecondInterface { ... } — any number of interfaces can follow the :. [S1]
• Each interface method must be implemented — the implementing class must provide a body for every method declared across ALL implemented interfaces. [S1]
• Still no shared state from interfaces — since interfaces can't contain fields (per the previous chapter), implementing multiple interfaces never brings in multiple sets of DATA, only multiple sets of METHOD CONTRACTS. [S1]

📖 세부 내용 (Details)

• Two interfaces: interface IFirstInterface { void myMethod(); } interface ISecondInterface { void myOtherMethod(); }. [S1]
• Combined implementation: class DemoClass : IFirstInterface, ISecondInterface { public void myMethod() { Console.WriteLine("Some text.."); } public void myOtherMethod() { Console.WriteLine("Some other text..."); } }. [S1]
• Usage: DemoClass myObj = new DemoClass(); myObj.myMethod(); myObj.myOtherMethod(); → prints both messages. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• C++ 다중 상속의 데이터 상속과 달리 계약(메서드 시그니처)만 상속됨: C++의 다중 상속([[CPP Inheritance Multiple]])은 여러 베이스 클래스의 실제 필드와 구현을 함께 물려받았지만, C#의 다중 인터페이스 구현은 인터페이스가 필드를 가질 수 없으므로 메서드 시그니처(계약)만 여러 개 물려받는다는 점이 확인됨 — 실질적으로 더 제한된 형태의 "다중 상속". [S1]

🛠️ 적용 사례 (Applied in summary)

IFirstInterface와 ISecondInterface 두 인터페이스를 DemoClass 하나가 동시에 구현해 두 메서드를 모두 호출하는 예제가 원문에서 직접 실전 활용 사례로 제시됨. [S1]

💻 코드 패턴 (Code patterns)

Implementing two interfaces in one class, comma-separated (C#):

interface IFirstInterface { void myMethod(); }
interface ISecondInterface { void myOtherMethod(); }

class DemoClass : IFirstInterface, ISecondInterface
{
    public void myMethod() { Console.WriteLine("Some text.."); }
    public void myOtherMethod() { Console.WriteLine("Some other text..."); }
}

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.83
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: C# Tutorial
• 관련 개념: CSharp Interface, CSharp Enums, CPP Inheritance Multiple
• 참조 맥락: Interface 섹션의 마지막 챕터 — Enums 섹션으로 이어짐.

📚 출처 (Sources)

• [S1] W3Schools — C# Multiple Interfaces — https://www.w3schools.com/cs/cs_interface_multi.php

📝 변경 이력 (Change history)

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