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_Syntax.md

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+---
+id: javascript-syntax
+title: "JavaScript Syntax"
+category: "Frontend"
+status: "draft"
+verification_status: "conceptual"
+canonical_id: ""
+aliases: ["JS syntax", "literals", "identifiers", "case sensitivity", "camelCase"]
+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", "syntax", "identifiers"]
+raw_sources: ["https://www.w3schools.com/js/js_syntax.asp"]
+applied_in: []
+github_commit: ""
+---
+
+# [[JavaScript Syntax]]
+
+## 🎯 한 줄 통찰 (One-line insight)
+JavaScript syntax is the set of rules for how programs are constructed — built from values (literals and variables), keywords, operators, expressions, and identifiers, all of which are case-sensitive. [S1]
+
+## 🧠 핵심 개념 (Core concepts)
+- **Syntax = construction rules** — JavaScript syntax is the set of rules for how JavaScript programs are constructed. [S1]
+- **Two kinds of values** — fixed values (literals) and variable values (variables). [S1]
+- **Literals** — numbers are written with or without decimals; strings are text written within double or single quotes. [S1]
+- **Keywords create variables** — the `let` and `const` keywords are used to create variables; keywords are case-sensitive. [S1]
+- **Variables store data** — variables are containers for storing data values and must have unique names. [S1]
+- **JavaScript is case-sensitive** — `lastName` and `lastname` are two different variables. [S1]
+
+## 🧩 추출된 패턴 (Extracted patterns)
+- **Declare → assign → compute** — declare variables with `let`/`const`, assign values, then combine them in expressions. [S1]
+- **Lower camelCase naming** — hyphens are not allowed; underscores and PascalCase are possible, but JavaScript programmers tend to use lower camelCase. [S1]
+- **Identifier rules** — start with a letter, `_`, or `$`; later characters may include digits; never a reserved keyword; case-sensitive. [S1]
+
+## 📖 세부 내용 (Details)
+**JavaScript Syntax** — JavaScript syntax is the rules for how JavaScript programs are constructed. A basic program declares variables, computes values, and may contain comments: [S1]
+```javascript
+// How to Declare variables:
+let x = 5;
+let y = 6;
+
+// How to Compute values:
+let z = x + y;
+
+// I am a Comment. I do Nothing
+```
+
+**JavaScript Values** — The JavaScript syntax defines two types of values: fixed values (literals) and variable values (variables). [S1]
+
+**JavaScript Literals** — Numbers are written with or without decimals: [S1]
+```javascript
+10.50
+
+1001
+```
+Strings are text, written within double or single quotes: [S1]
+```javascript
+"John Doe"
+
+'John Doe'
+```
+
+**JavaScript Keywords** — JavaScript keywords are used to identify actions to be performed. The `let` and `const` keywords tell the browser to create variables: [S1]
+```javascript
+let x = 5;
+
+const fname = "John";
+```
+
+**JavaScript Variables** — In a programming language, variables are used to store data values. JavaScript uses the keywords `var`, `let`, and `const` to declare variables. An equal sign (`=`) is used to assign values to variables: [S1]
+```javascript
+// Define x as a variable
+let x;
+
+// Assign the value 6 to x
+x = 6;
+```
+
+**JavaScript Operators** — JavaScript uses arithmetic operators (`+`, `-`, `*`, `/`) to compute values, and an assignment operator (`=`) to assign values to variables: [S1]
+```javascript
+let x = 5;
+let y = 6;
+let sum = x + y;
+```
+
+**JavaScript Expressions** — An expression is a combination of values, variables, and operators which computes to a value. The computation is called an evaluation. Expressions can also contain variable values, and the values can be of various types, such as numbers and strings: [S1]
+```javascript
+5 * 10
+```
+```javascript
+(5 + 6) * 10
+```
+```javascript
+x * 10
+```
+```javascript
+"John" + " " + "Doe"
+```
+
+**JavaScript Identifiers / Names** — Identifiers are JavaScript names, used to name variables, keywords, and functions. The rules for legal names are: [S1]
+- Names can contain letters, digits, underscores, and dollar signs.
+- Names must begin with a letter, `$`, or `_`.
+- Names are case-sensitive.
+- Reserved words (like JavaScript keywords) cannot be used as names.
+
+**JavaScript is Case Sensitive** — All JavaScript identifiers are case-sensitive. The variables `lastName` and `lastname` are two different variables: [S1]
+```javascript
+let lastName = "Doe";
+let lastname = "Peterson";
+```
+
+**JavaScript and Camel Case** — Historically, programmers have used different ways of joining multiple words into one variable name: hyphens (not allowed in JavaScript — they are reserved for subtractions), underscores, Upper Camel Case (Pascal Case), and Lower Camel Case. JavaScript programmers tend to use camel case that starts with a lowercase letter. [S1]
+
+## 🛠️ 적용 사례 (Applied in summary)
+The page's own snippets are the canonical applied examples — declaring with `let`/`const`, computing `x + y`, evaluating expressions like `(5 + 6) * 10`, and the case-sensitive `lastName`/`lastname` pair. No external project/commit applications found in the source.
+
+## 💻 코드 패턴 (Code patterns)
+Declare, assign, compute:
+```javascript
+let x = 5;
+let y = 6;
+let z = x + y;
+```
+String concatenation expression:
+```javascript
+"John" + " " + "Doe"
+```
+
+## ⚖️ 비교 및 선택 기준 (Comparison & decision criteria)
+For joining multiple words into one identifier, the source presents the options and JavaScript's convention: [S1]
+
+| Style | Example | JavaScript stance |
+|-------|---------|-------------------|
+| Hyphens | `first-name` | Not allowed (reserved for subtraction) |
+| Underscores | `first_name` | Possible |
+| Upper Camel Case (Pascal) | `FirstName` | Possible |
+| Lower Camel Case | `firstName` | Preferred convention by JavaScript programmers |
+
+## ⚖️ 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 Statements]], [[JavaScript Variables]], [[JavaScript Comments]]
+- **참조 맥락:** The grammar layer underpinning every other JavaScript topic.
+
+## 📚 출처 (Sources)
+- [S1] W3Schools — JavaScript Syntax — https://www.w3schools.com/js/js_syntax.asp
+
+## 📝 변경 이력 (Change history)
+- 2026-06-23: Initial draft synthesized from the W3Schools "JavaScript Syntax" page (Astra wiki-curation, P-Reinforce v3.1 format).