---
id: c-booleans
title: "C Booleans"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["bool type", "stdbool.h", "C 불리언"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.86
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["c", "programming-language", "w3schools", "booleans", "stdbool"]
raw_sources: ["https://www.w3schools.com/c/c_booleans.php"]
applied_in: []
github_commit: ""
---

# [[C Booleans]]

## 🎯 한 줄 통찰 (One-line insight)
`bool` is NOT a built-in C type like `int` or `char` — it was only added in C99 and requires explicitly including `<stdbool.h>`, meaning code written for older/stricter C standards, or code that forgets this include, has no `bool` keyword at all and must fall back to plain `int` with 1/0 conventions instead. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`bool`** (C99+, via `<stdbool.h>`) — a type representing exactly two values: `true` or `false`. [S1]
- **Underlying integer representation** — booleans print as integers: `1` (or any non-zero) for true, `0` for false, using the `%d` specifier. [S1]
- **Bool-to-bool comparison** — bool variables can be compared with `==` just like any other value (e.g. checking if two bools are both true). [S1]
- **Storing comparison results** — a comparison's result (already a 1/0 value) can be stored directly in a `bool` variable for readability and reuse. [S1]

## 📖 세부 내용 (Details)
- Declaring and printing bools: `bool isProgrammingFun = true; bool isFishTasty = false; printf("%d", isProgrammingFun); // 1 printf("%d", isFishTasty); // 0`. [S1]
- Comparing two bool variables: `bool isHamburgerTasty = true; bool isPizzaTasty = true; printf("%d", isHamburgerTasty == isPizzaTasty); // 1`. [S1]
- Storing a comparison result in a bool: `int x = 10; int y = 9; bool isGreater = x > y; printf("%d", isGreater); // 1`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **bool은 C의 내장 타입이 아님**: int나 char와 달리 bool은 C99에서 도입되었고 반드시 <stdbool.h>를 포함해야 사용 가능하다는 점이 명시적으로 강조됨. [S1]

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 비교 결과를 bool 변수에 저장해 재사용하는 것이 코드 가독성을 높이는 실전 습관으로 권장된다. [S1]

## 💻 코드 패턴 (Code patterns)
Storing a comparison's result in a bool variable for readability (C):
```c
#include <stdbool.h>
int x = 10;
int y = 9;
bool isGreater = x > y;
printf("%d", isGreater); // Prints 1 (true)
```

## ✅ 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:** [[C Random Numbers]], [[C Operators Comparison]], [[C Booleans RealLife]]
- **참조 맥락:** 불리언 섹션 첫 챕터 — 불리언 실전 예제(Booleans RealLife) 챕터로 이어짐.

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

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