---
id: c-conditions-else
title: "C Else"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["else statement", "C else 문"]
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: ["c", "programming-language", "w3schools", "conditions", "else"]
raw_sources: ["https://www.w3schools.com/c/c_conditions_else.php"]
applied_in: []
github_commit: ""
---

# [[C Else]]

## 🎯 한 줄 통찰 (One-line insight)
Naming a boolean condition variable descriptively (`isDay` instead of a raw `time < 18` expression) doesn't change the program's behavior at all — it's purely a communication device for future readers — and the source explicitly frames this as its entire justification: "makes it easy to understand what the condition means," not a performance or correctness improvement. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`else`** — runs a block of code when the paired `if` condition is false; there is no separate condition to check for `else` itself. [S1]
- **Mutually exclusive branches** — exactly one of the `if` or `else` block executes, never both, never neither. [S1]
- **Descriptive boolean naming** — storing a condition in a variable like `isDay` documents the condition's MEANING, not just its mechanics. [S1]

## 📖 세부 내용 (Details)
- Basic if/else: `int time = 20; if (time < 18) { printf("Good day."); } else { printf("Good evening."); } // Outputs "Good evening."`. [S1]
- Same logic with a descriptively-named boolean: `bool isDay = time < 18; if (isDay) { printf("Good day."); } else { printf("Good evening."); }`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- 현재까지 발견된 모순 사항 없음 (No contradictions found in available sources).

## 🛠️ 적용 사례 (Applied in summary)
시간(time)이 18보다 작은지에 따라 "좋은 하루"/"좋은 저녁"을 출력하는 예제가 원문에서 직접 실전 활용 사례로 제시됨(시간대 기반 인사말 로직). [S1]

## 💻 코드 패턴 (Code patterns)
Naming a boolean condition descriptively for readability (C):
```c
int time = 20;
bool isDay = time < 18;
if (isDay) {
  printf("Good day.");
} else {
  printf("Good evening.");
}
```

## ✅ 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:** [[C Conditions]], [[C Conditions ElseIf]]
- **참조 맥락:** else 문 — else if 문(Conditions ElseIf) 챕터로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — C Else — https://www.w3schools.com/c/c_conditions_else.php

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