---
id: php-oop-static-properties
title: "PHP OOP Static Properties"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["static properties", "PHP 정적 속성"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.89
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["php", "programming", "w3schools", "oop", "static"]
raw_sources: ["https://www.w3schools.com/php/php_oop_static_properties.asp"]
applied_in: []
github_commit: ""
---

# [[PHP OOP Static Properties]]

## 🎯 한 줄 통찰 (One-line insight)
A child class can read a parent's static property TWO different ways with different syntax for each — `x::$value` (via the child's OWN class name, since it inherited the static property) or `parent::$value` from inside a method — showing that static properties are inherited and directly accessible through the child's name, unlike static methods which more often route through `parent::`. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`static` property** — declared like `public static $prop = value;`; accessible without instantiating the class. [S1]
- **Access via `ClassName::$prop`** — the standard external access syntax (uses `$` before the property name, unlike static methods). [S1]
- **Access via `self::$prop`** — used inside a method of the same class. [S1]
- **Access via `parent::$prop`** — used inside a child class's method to reach the parent's static property. [S1]
- **Direct inherited access** — a static property is also directly reachable via the CHILD class name (`x::$value`) since it's inherited, without needing `parent::`. [S1]

## 📖 세부 내용 (Details)
- Direct static property access: `class pi { public static $value = 3.14159; } echo pi::$value;`. [S1]
- Access via self inside a method: `class pi { public static $value=3.14159; public function staticValue() { return self::$value; } } $pi = new pi(); echo $pi->staticValue();`. [S1]
- Child class access — both direct and via parent::: `class pi { public static $value=3.14159; } class x extends pi { public function xStatic() { return parent::$value; } } echo x::$value; // direct, works because inherited $x = new x(); echo $x->xStatic(); // via parent:: inside a method`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
소스에서 모순되는 정보는 발견되지 않음.

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 원주율(pi)처럼 클래스 전체가 공유하는 상수적 값을 정적 속성으로 표현하는 것이 대표 실전 사례다. [S1]

## 💻 코드 패턴 (Code patterns)
Accessing an inherited static property directly via the child class name (PHP):
```php
class pi {
    public static $value = 3.14159;
}
class x extends pi {
    public function xStatic() { return parent::$value; }
}
echo x::$value;          // direct access via child class name (inherited)
$x = new x();
echo $x->xStatic();      // access via parent:: inside a method
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.89
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[PHP Tutorial]]
- **관련 개념:** [[PHP OOP Static Methods]], [[PHP Namespaces]]
- **참조 맥락:** OOP 섹션의 마지막 — 네임스페이스(Namespaces) 섹션으로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — PHP OOP - Static Properties — https://www.w3schools.com/php/php_oop_static_properties.asp

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