---
id: cpp-conditions-logical
title: "C++ Logical Operators in Conditions"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["access control logic", "&& || ! in if", "C++ 조건문 논리 연산자"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.85
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["cpp", "programming-language", "w3schools", "conditions", "logical-operators"]
raw_sources: ["https://www.w3schools.com/cpp/cpp_conditions_logical.asp"]
applied_in: []
github_commit: ""
---

# [[CPP Logical Operators in Conditions]]

## 🎯 한 줄 통찰 (One-line insight)
The exact same nested access-control rule (`isLoggedIn && (isAdmin || securityLevel <= 2)`) and the exact same four worked-through securityLevel outcomes (1/2 granted, 3/4 denied) reappear identically from C's chapter — confirming this specific compound authorization pattern was deliberately carried over as the canonical teaching example for combining `&&`/`||` across both languages. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`&&` (AND)** — both conditions must be true. [S1]
- **`||` (OR)** — at least one condition must be true. [S1]
- **`!` (NOT)** — reverses a condition's truth value. [S1]
- **Nested logical composition** — parentheses group sub-conditions that combine with another condition via `&&`, mirroring real authorization rules. [S1]

## 📖 세부 내용 (Details)
- AND: `int a = 200, b = 33, c = 500; if (a > b && c > a) { cout << "Both conditions are true"; }`. [S1]
- OR: `if (a > b || a > c) { cout << "At least one condition is true"; }`. [S1]
- NOT: `int a = 33; int b = 200; if (!(a > b)) { cout << "a is NOT greater than b"; }`. [S1]
- Full access-control rule with worked-through outcomes: `bool isLoggedIn = true; bool isAdmin = false; int securityLevel = 3; if (isLoggedIn && (isAdmin || securityLevel <= 2)) { cout << "Access granted."; } else { cout << "Access denied."; }` — securityLevel 1 or 2 → granted; 3 or 4 → denied (unless isAdmin is true). [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- 현재까지 발견된 모순 사항 없음 (No contradictions found in available sources). C 챕터의 접근 제어 예제와 완전히 동일함이 확인됨.

## 🛠️ 적용 사례 (Applied in summary)
로그인 여부(isLoggedIn) + (관리자이거나(isAdmin) 보안등급이 2 이하(securityLevel <= 2))를 결합한 접근 제어 규칙이 원문에서 직접 실전 활용 사례로 제시됨. [S1]

## 💻 코드 패턴 (Code patterns)
Nested AND/OR logic for a real-world access-control rule (C++):
```cpp
bool isLoggedIn = true;
bool isAdmin = false;
int securityLevel = 3; // 1 = highest
if (isLoggedIn && (isAdmin || securityLevel <= 2)) {
  cout << "Access granted.";
} else {
  cout << "Access denied.";
}
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.85
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[C++ Tutorial]]
- **관련 개념:** [[CPP Conditions Shorthand]], [[CPP Operators Logical]], [[CPP Conditions Nested]]
- **참조 맥락:** 조건문 내 논리 연산자 — 중첩 if(Conditions Nested) 챕터로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — C++ Logical Operators in Conditions — https://www.w3schools.com/cpp/cpp_conditions_logical.asp

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