---
id: php-operators
title: "PHP Operators"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["PHP 연산자"]
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", "operators"]
raw_sources: ["https://www.w3schools.com/php/php_operators.asp"]
applied_in: []
github_commit: ""
---

# [[PHP Operators]]

## 🎯 한 줄 통찰 (One-line insight)
PHP distinguishes `==` (equal) from `===` (identical) at the type level, not just the value level — `$x === $y` requires BOTH the value AND the data type to match, meaning `5 == "5"` is true but `5 === "5"` is false, a distinction that extends identically to array comparison operators too. [S1]

## 🧠 핵심 개념 (Core concepts)
- **8 operator groups** — Arithmetic, Assignment, Comparison, Increment/Decrement, Logical, String, Array, Conditional. [S1]
- **`==` vs `===`** — equal (loose, value only) vs. identical (strict, value + type). [S1]
- **`<=>`** (spaceship, PHP 7+) — returns negative/zero/positive based on relative order. [S1]
- **Pre vs. post increment** — `++$x` returns the NEW value; `$x++` returns the OLD value, both then incrementing. [S1]
- **String operators** — `.` (concat), `.=` (concat-assign). [S1]
- **Array operators** — `+` (union), `==`/`===` (equality/identity with type-sensitivity difference). [S1]
- **`?:`** (ternary) and **`??`** (null coalescing, PHP 7+) — conditional shorthand operators. [S1]

## 📖 세부 내용 (Details)
- Comparison table includes: `==`, `===`, `!=`, `<>`, `!==`, `>`, `<`, `>=`, `<=`, `<=>` (spaceship). [S1]
- Increment/decrement: `++$x` (pre-increment: increments then returns), `$x++` (post-increment: returns then increments). [S1]
- Logical operators: `and`/`&&`, `or`/`||`, `xor`, `!`. [S1]
- Null coalescing: `$x = expr1 ?? expr2;` — `expr2` used if `expr1` doesn't exist or is NULL. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **== 와 ===의 차이**: 값만 비교(==)하는 것과 값+타입을 모두 비교(===)하는 것이 배열 비교에도 동일하게 적용된다는 점이 명시됨. [S1]

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — null 병합 연산자(??)가 기본값 설정 로직에서 자주 쓰이는 실전 패턴이다. [S1]

## 💻 코드 패턴 (Code patterns)
Null coalescing operator for default values (PHP):
```php
$x = $expr1 ?? "default value"; // uses $expr1 unless it's NULL/unset
```

## ✅ 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 If Else]], [[PHP If Operators]], [[PHP If Shorthand]]
- **참조 맥락:** 모든 연산자의 개요 — 조건문(If Else) 챕터로 이어짐.

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

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