---
id: php-includes
title: "PHP Includes"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["include vs require", "PHP 파일 포함"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.9
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["php", "programming", "w3schools", "include", "require"]
raw_sources: ["https://www.w3schools.com/php/php_includes.asp"]
applied_in: []
github_commit: ""
---

# [[PHP Includes]]

## 🎯 한 줄 통찰 (One-line insight)
`include` and `require` behave identically on SUCCESS but diverge sharply on FAILURE — a missing file only produces a warning with `include` (script continues, later code still runs), while the same missing file with `require` triggers a fatal error that halts script execution entirely, making the choice a statement about how critical that file is to the page working at all. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`include 'file';`** / **`require 'file';`** — insert a file's content into the calling file. [S1]
- **Failure behavior difference** — `include` → `E_WARNING`, script continues; `require` → `E_ERROR` (fatal), script stops. [S1]
- **When to use `include`** — non-critical files like headers, footers, navigation menus (page can still render without them). [S1]
- **When to use `require`** — critical files like configuration or database connections (page is meaningless without them). [S1]
- **Included files share variable scope** — variables defined in an included file become usable in the calling file. [S1]

## 📖 세부 내용 (Details)
- Include a footer: `<?php include 'footer.php';?>`. [S1]
- Include a nav menu: `<div class="menu"><?php include 'menu.php';?></div>`. [S1]
- Include shares variables: `vars.php` defines `$color='red'; $car='BMW';`; the including file can then `echo "I have a $color $car.";` after `include 'vars.php';`. [S1]
- include on missing file (continues): `<?php include 'noFileExists.php'; echo "I have a $color $car."; ?>` — the echo still runs (with warning), though `$color`/`$car` are undefined here since the file wasn't found. [S1]
- require on missing file (halts): `<?php require 'noFileExists.php'; echo "I have a $color $car."; ?>` — the echo NEVER executes; script dies at the require line. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **실패 시 동작의 근본적 차이**: include는 경고만 내고 스크립트가 계속 실행되지만, require는 치명적 에러를 내고 스크립트 실행이 완전히 중단된다는 점이 대비 예제로 직접 증명됨. [S1]

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 모든 페이지가 공유하는 표준 헤더/푸터/메뉴 파일을 include로 재사용하는 것이 실전 코드 재사용의 대표 패턴이다. [S1]

## 💻 코드 패턴 (Code patterns)
require halts execution on failure, unlike include (PHP):
```php
<?php require 'noFileExists.php'; // fatal error — script dies here
echo "This line never runs.";
?>
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.90
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[PHP Tutorial]]
- **관련 개념:** [[PHP Date]], [[PHP Files]], [[PHP Variables Scope]]
- **참조 맥락:** 코드 재사용을 위한 파일 포함 — 파일 처리(Files) 섹션으로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — PHP Include Files — https://www.w3schools.com/php/php_includes.asp

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