---
id: cpp-exceptions
title: "C++ Exceptions"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["try catch throw", "exception handling", "catch all (...)", "C++ 예외 처리"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.88
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["cpp", "programming-language", "w3schools", "exceptions", "try-catch"]
raw_sources: ["https://www.w3schools.com/cpp/cpp_exceptions.asp"]
applied_in: []
github_commit: ""
---

# [[CPP Exceptions]]

## 🎯 한 줄 통찰 (One-line insight)
C++ has the try/catch/throw mechanism that C's Error Handling chapter EXPLICITLY said C lacks entirely — meaning this is the single biggest error-handling divergence between the two languages: where C forced programmers into manual NULL-checking, `errno`, and `perror()` workarounds, C++ provides genuine LANGUAGE-LEVEL exception handling that can catch ANY thrown value, even without knowing its type in advance (via the `catch (...)` catch-all syntax). [S1]

## 🧠 핵심 개념 (Core concepts)
- **Exception** — C++'s technical term for the error that occurs when something goes wrong; "C++ will THROW an exception." [S1]
- **`try`** — defines the code block to test for possible errors. [S1]
- **`throw`** — triggers an exception, optionally carrying a VALUE (of any type, e.g. `throw 505;` or `throw age;`). [S1]
- **`catch (type param)`** — handles the exception; its parameter TYPE must match what was thrown (e.g. `catch (int errorCode)` for an `int`-typed throw). [S1]
- **`catch (...)`** — the "three dots" catch-all syntax; handles ANY exception type when you don't know (or don't need to distinguish) the thrown type in advance. [S1]
- **No error = catch block skipped** — if the `try` block never throws, the `catch` block simply doesn't run. [S1]

## 📖 세부 내용 (Details)
- Basic throw/catch with a custom error code: `try { throw 505; } catch (int errorCode) { cout << "Error occurred: " << errorCode; }`. [S1]
- Real-life age-check example throwing the actual failing value: `try { int age = 15; if (age >= 18) { cout << "Access granted."; } else { throw (age); } } catch (int myNum) { cout << "Access denied. Age is: " << myNum; }`. [S1]
- Catch-all syntax when the thrown type is unknown: `try { ... throw 505; } catch (...) { cout << "Access denied."; }` — handles the exception without needing to declare its type. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **C에는 없던 진짜 예외 처리 메커니즘**: C의 Error Handling 챕터가 "C에는 try/catch가 없다"고 명시했던 것과 정반대로, C++는 try/throw/catch라는 언어 차원의 예외 처리를 제공하며, catch(...)로 타입을 몰라도 모든 예외를 잡을 수 있다는 점까지 C에는 없던 기능으로 확인됨. [S1]

## 🛠️ 적용 사례 (Applied in summary)
사용자의 나이가 18세 미만이면 예외를 던지고 접근을 거부하는 age-check 예제가 원문에서 직접 실전 활용 사례로 제시됨. [S1]

## 💻 코드 패턴 (Code patterns)
Catching any exception type without needing to know it in advance (C++):
```cpp
try {
  int age = 15;
  if (age >= 18) {
    cout << "Access granted - you are old enough.";
  } else {
    throw 505;
  }
}
catch (...) { // catches any exception type
  cout << "Access denied - You must be at least 18 years old.\n";
}
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.88
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[C++ Tutorial]]
- **관련 개념:** [[CPP Errors]], [[CPP Input Validation]], [[C Error Handling]]
- **참조 맥락:** 예외 처리 — 입력 검증(Input Validation) 챕터로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — C++ Exceptions — https://www.w3schools.com/cpp/cpp_exceptions.asp

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