---
id: csharp-switch
title: "C# Switch"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["switch case break default C#", "C# 스위치문"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.82
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["csharp", "programming-language", "w3schools", "switch"]
raw_sources: ["https://www.w3schools.com/cs/cs_switch.php"]
applied_in: []
github_commit: ""
---

# [[CSharp Switch]]

## 🎯 한 줄 통찰 (One-line insight)
The `switch(expression) { case x: ... break; default: ... break; }` skeleton is structurally identical to C/C++'s switch statement — same `case`/`break`/`default` keywords, same "evaluate once, compare against each case" model — making Switch the fourth chapter in the C# series (after Comments, Operators, Special Characters) where the answer to "what's different from C++" is essentially nothing at the syntax level shown here. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`switch(expression)`** — evaluated exactly ONCE, then compared against each `case` value in order. [S1]
- **`case x:`** — if the switch expression matches `x`, that block's code runs. [S1]
- **`break`** — exits the switch block immediately once a match's code has run, preventing execution from continuing into subsequent cases; described as saving execution time by skipping the rest of the block. [S1]
- **`default:`** — optional; runs when NO case matches the expression. [S1]

## 📖 세부 내용 (Details)
- Weekday-name example: `switch (day) { case 1: Console.WriteLine("Monday"); break; ... case 7: Console.WriteLine("Sunday"); break; }` with `day = 4` → outputs `"Thursday"`. [S1]
- Default fallback example: `switch (day) { case 6: ...Saturday...; break; case 7: ...Sunday...; break; default: Console.WriteLine("Looking forward to the Weekend."); break; }` with `day = 4` (no matching case) → outputs `"Looking forward to the Weekend."` via `default`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **switch 구조가 C/C++와 동일**: `switch`/`case`/`break`/`default` 키워드와 전체 구조가 C/C++의 switch문과 차이가 없다는 점이 확인됨 — Comments, Operators, Special Characters에 이은 네 번째 "구조 동일" 챕터. [S1]

## 🛠️ 적용 사례 (Applied in summary)
요일 번호(day)를 받아 요일 이름을 출력하는 switch문과, 매치되는 case가 없을 때 default로 넘어가는 예제가 원문에서 직접 실전 활용 사례로 제시됨. [S1]

## 💻 코드 패턴 (Code patterns)
Switch with break and default (C#):
```csharp
int day = 4;
switch (day)
{
    case 1:
        Console.WriteLine("Monday");
        break;
    case 4:
        Console.WriteLine("Thursday");
        break;
    default:
        Console.WriteLine("Looking forward to the Weekend.");
        break;
}
// Outputs "Thursday"
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.82
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[C# Tutorial]]
- **관련 개념:** [[CSharp Conditions Shorthand]], [[CSharp While Loop]], [[CPP Switch]]
- **참조 맥락:** Switch 섹션의 유일 챕터 — Loops 섹션으로 이어짐.

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

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