---
id: php-oop-classes-objects
title: "PHP OOP Classes Objects"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["instanceof", "PHP 클래스와 객체"]
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", "oop", "classes"]
raw_sources: ["https://www.w3schools.com/php/php_oop_classes_objects.asp"]
applied_in: []
github_commit: ""
---

# [[PHP OOP Classes Objects]]

## 🎯 한 줄 통찰 (One-line insight)
`$this` inside a method always refers to the specific object it was called on — so `$apple->set_details('Apple', 'Red')` and `$banana->set_details('Banana', 'Yellow')` run the EXACT SAME method code, yet each object ends up with its own independent property values, since `$this` resolves differently per call. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`class` keyword** — defines a class with properties (variables) and methods (functions) inside `{ }`. [S1]
- **`$this`** — refers to the current object's own properties/methods within a method. [S1]
- **`new` keyword** — creates an object instance from a class. [S1]
- **`instanceof`** — checks whether an object belongs to a specific class, returning a boolean. [S1]

## 📖 세부 내용 (Details)
- Class definition: `class Fruit { public $name; public $color; function set_details($name, $color) { $this->name = $name; $this->color = $color; } function get_details() { echo "Name: " . $this->name . ". Color: " . $this->color .".<br>"; } }`. [S1]
- Object creation and independent state: `$apple = new Fruit(); $apple->set_details('Apple', 'Red'); $banana = new Fruit(); $banana->set_details('Banana', 'Yellow');` — each object holds distinct values. [S1]
- instanceof check: `var_dump($apple instanceof Fruit); // true`. [S1]

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

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — Fruit 클래스에서 Apple/Banana 객체를 각각 생성하는 것이 인스턴스 독립성의 대표 예시다. [S1]

## 💻 코드 패턴 (Code patterns)
Two independent object instances from the same class (PHP):
```php
class Fruit {
    public $name;
    public $color;
    function set_details($name, $color) {
        $this->name = $name;
        $this->color = $color;
    }
}
$apple = new Fruit();
$apple->set_details('Apple', 'Red');
$banana = new Fruit();
$banana->set_details('Banana', 'Yellow');
```

## ✅ 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 OOP What Is]], [[PHP OOP Constructor]], [[PHP OOP Access Modifiers]]
- **참조 맥락:** 클래스/객체 선언 기초 — 생성자(Constructor) 챕터로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — PHP OOP - Classes and Objects — https://www.w3schools.com/php/php_oop_classes_objects.asp

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