docs(10_Wiki): W3Schools 위키화 — HTML/CSS/JavaScript(core)

W3Schools 튜토리얼을 P-Reinforce v3.1 포맷으로 위키화(영어 본문, 한/영 섹션 헤더).
- Topic_HTML: 59문서 (튜토리얼+예제, 레퍼런스/메타 제외)
- Topic_CSS: 190문서 (메인 + Advanced/Flexbox/Grid/RWD 전체)
- Topic_JavaScript: 120문서 (코어 언어; Temporal/DOM상세/BOM/WebAPI/AJAX/jQuery/Graphics 등은 후속)
각 폴더 00_INDEX.md(MOC) 포함. 코드 verbatim, 미확인분은 "Not found in source" 표기.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

10_Wiki/Topic_JavaScript/JavaScript_toString.md

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+---
+id: javascript-tostring
+title: "JavaScript toString"
+category: "Frontend"
+status: "draft"
+verification_status: "conceptual"
+canonical_id: ""
+aliases: ["toString", "toString()", "JS toString", "array toString", "number toString", "object toString"]
+duplicate_of: ""
+source_trust_level: "B"
+confidence_score: 0.88
+created_at: 2026-06-23
+updated_at: 2026-06-23
+review_reason: ""
+merge_history: []
+tags: ["javascript", "js", "web", "frontend", "w3schools", "tostring", "type-conversion"]
+raw_sources: ["https://www.w3schools.com/js/js_tostring.asp"]
+applied_in: []
+github_commit: ""
+---
+
+# [[JavaScript toString]]
+
+## 🎯 한 줄 통찰 (One-line insight)
+`toString()` is a built-in method that converts a variable or value to a string, available across many data types — numbers, arrays, dates, and objects. [S1]
+
+## 🧠 핵심 개념 (Core concepts)
+- **General-purpose converter** — `toString()` converts a variable (or a value) to a string. [S1]
+- **Built-in across types** — It is a built-in method for many data types, including numbers, arrays, dates, and objects. [S1]
+- **Array → comma-separated** — On an array, `toString()` returns the array elements as a comma separated string. [S1]
+- **Date → human-readable** — On a date, `toString()` returns a human-readable date and time string. [S1]
+- **Number → string, with optional base** — On a number, it returns the number as a string; it can accept a base argument (e.g. `2` for binary). [S1]
+- **Function → source code** — On a function, `toString()` returns the source code of the function as a string. [S1]
+- **Object → `[object Object]`** — On an object, `toString()` returns `"[object Object]"` by default, but can be overridden in the object definition. [S1]
+
+## 🧩 추출된 패턴 (Extracted patterns)
+- **Display-formatting** — Convert data to a readable format for display. [S1]
+- **Type-compatibility guard** — Ensure a string type when a string is required. [S1]
+- **Radix conversion** — Pass a base to `Number.prototype.toString()` (e.g. `x.toString(2)`) to render numbers in other bases. [S1]
+- **Custom representation** — Override `toString()` in an object definition to give it a meaningful string form for UIs or debugging. [S1]
+
+## 📖 세부 내용 (Details)
+**JavaScript toString() Method**
+The JavaScript `toString()` method converts a variable (or a value) to a string. It is a built-in method for many data types, including numbers, arrays, dates, and objects. The method is useful for: converting data to a readable format for display; ensuring type compatibility when a string is required; customizing objects for user interfaces; and customizing objects for debugging. [S1]
+
+**JavaScript Array toString()**
+When used on an array, `toString()` returns the array elements as a comma separated string. [S1]
+```javascript
+const fruits = ["Banana", "Orange", "Apple", "Mango"];
+let myList = fruits.toString();
+```
+
+**JavaScript Date toString()**
+When used on a date, `toString()` returns a human-readable date and time string. Convert a date object to a string: [S1]
+```javascript
+const d = new Date();
+let text = d.toString();
+```
+
+**JavaScript Number toString()**
+When used on a number, `toString()` returns the number as a string. [S1]
+```javascript
+let x = 123;
+let text = x.toString();
+```
+Convert a number to a string, using base 2 (binary): [S1]
+```javascript
+let x = 123;
+let text = x.toString(2);
+```
+
+**JavaScript Function toString()**
+When used on a function, `toString()` returns the source code of the function as a string. [S1]
+
+**JavaScript Object toString()**
+When used on an object, `toString()` returns `"[object Object]"`. To provide a meaningful string representation, it can be overridden in the object definition: [S1]
+```javascript
+let person = {
+  firstname: "John",
+  lastname: "Doe",
+}
+let text = person.toString();
+```
+
+## 🛠️ 적용 사례 (Applied in summary)
+The page's own snippets are the canonical applied examples — `fruits.toString()`, `d.toString()`, `x.toString(2)`, and a `person` object's `toString()`. No external project/commit applications found in the source.
+
+## 💻 코드 패턴 (Code patterns)
+Convert a number to a binary string (language: JavaScript):
+```javascript
+let x = 123;
+let text = x.toString(2);
+```
+Convert an array to a comma-separated string:
+```javascript
+const fruits = ["Banana", "Orange", "Apple", "Mango"];
+let myList = fruits.toString();
+```
+
+## ⚖️ 모순 및 업데이트 (Contradictions & updates)
+No contradictions found in the source.
+
+## ✅ 검증 상태 및 신뢰도
+- **상태:** draft
+- **검증 단계:** conceptual (실제 적용 사례 발견 시 applied/validated로 승격 가능)
+- **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:** [[JavaScript Tutorial]]
+- **관련 개념:** [[JavaScript toLocaleString]], [[JavaScript Type Conversion]], [[JavaScript Object Types Note]], [[JavaScript Introduction]]
+- **참조 맥락:** Referenced whenever a value must be rendered as text — output, logging, or radix conversion.
+
+## 📚 출처 (Sources)
+- [S1] W3Schools — JavaScript toString — https://www.w3schools.com/js/js_tostring.asp
+
+## 📝 변경 이력 (Change history)
+- 2026-06-23: Initial draft synthesized from the W3Schools "JavaScript toString" page (Astra wiki-curation, P-Reinforce v3.1 format).