2nd/10_Wiki/Topic_JavaScript/JavaScript_JSON_Syntax.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
json-syntax	JSON Syntax	Frontend	draft	conceptual		JSON syntax JSON rules name/value pairs JSON keys JSON files		B	0.89	2026-06-23	2026-06-23			javascript js web frontend w3schools json syntax	https://www.w3schools.com/js/js_json_syntax.asp

JSON Syntax

🎯 한 줄 통찰 (One-line insight)

JSON syntax is derived from JavaScript object notation — name/value pairs separated by commas, objects in curly braces, arrays in square brackets — but it is stricter than JavaScript: keys and string values must always use double quotes. [S1]

🧠 핵심 개념 (Core concepts)

• Four syntax rules — data is in name/value pairs; data is separated by commas; curly braces hold objects; square brackets hold arrays. [S1]
• JSON keys must be strings in double quotes — {"name":"John"}, whereas JavaScript keys can be strings, numbers, or identifier names ({name:"John"}). [S1]
• JSON string values require double quotes — {"name":"John"}; JavaScript allows double or single quotes ({name:'John'}). [S1]
• JSON is almost identical to JavaScript objects — and JavaScript arrays can also be written as JSON. [S1]
• File facts — the file type for JSON files is .json; the MIME type for JSON text is application/json. [S1]

🧩 추출된 패턴 (Extracted patterns)

• Name/value (key/value) pair — a field name in double quotes, a colon, then a value: "name":"John". [S1]
• Stricter-than-JS rule — JSON is a subset: it forbids the looser key/quote forms JavaScript allows. [S1]
• Object access patterns carry over — a JavaScript object can be read/modified via dot or bracket notation. [S1]

📖 세부 내용 (Details)

JSON syntax rules JSON syntax is derived from JavaScript object notation syntax: data is in name/value pairs; data is separated by commas; curly braces hold objects; square brackets hold arrays. [S1]

JSON data — a name and a value JSON data is written as name/value pairs (aka key/value pairs). A name/value pair consists of a field name (in double quotes), followed by a colon, followed by a value: [S1]

"name":"John"

JSON names require double quotes. [S1]

JSON evaluates to JavaScript objects The JSON format is almost identical to JavaScript objects. In JSON, keys must be strings, written with double quotes — JSON: [S1]

{"name":"John"}

In JavaScript, keys can be strings, numbers, or identifier names — JavaScript: [S1]

{name:"John"}

JSON values In JSON, values must be one of the following data types: a string, a number, an object, an array, a boolean, or null. In JavaScript, values can be all of the above, plus any other valid JavaScript expression, including a function, a date, or undefined. [S1]

In JSON, string values must be written with double quotes — JSON: [S1]

{"name":"John"}

In JavaScript, you can write string values with double or single quotes — JavaScript: [S1]

{name:'John'}

JavaScript objects With JavaScript you can create an object and assign data to it: [S1]

person = {name:"John", age:31, city:"New York"};

You can access a JavaScript object like this: [S1]

// returns John
person.name;

It can also be accessed like this: [S1]

// returns John
person["name"];

Data can be modified like this: [S1]

person.name = "Gilbert";

It can also be modified like this: [S1]

person["name"] = "Gilbert";

You will learn how to convert JavaScript objects into JSON later in this tutorial. [S1]

JavaScript arrays as JSON The same way JavaScript objects can be written as JSON, JavaScript arrays can also be written as JSON. You will learn more about objects and arrays later in this tutorial. [S1]

JSON files The file type for JSON files is .json. The MIME type for JSON text is application/json. [S1]

🛠️ 적용 사례 (Applied in summary)

The applied examples on the page are object creation, access (dot and bracket), and modification (dot and bracket) on a person object. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Create, access, and modify a JavaScript object:

person = {name:"John", age:31, city:"New York"};
person.name;          // returns John
person["name"];       // returns John
person.name = "Gilbert";
person["name"] = "Gilbert";

⚖️ 비교 및 선택 기준 (Comparison & decision criteria)

JSON vs JavaScript object literals — JSON is the stricter subset: [S1]

• Keys — JSON requires string keys in double quotes; JavaScript allows strings, numbers, or identifier names.
• String values — JSON requires double quotes; JavaScript allows double or single quotes.
• Value types — JSON values must be string, number, object, array, boolean, or null; JavaScript additionally allows functions, dates, undefined, and any valid JS expression.
• When to use which — use JSON's stricter form for any data meant to be transported or stored as text; use full JS object syntax for in-program objects.

⚖️ 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: 0.89
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: JavaScript Tutorial
• 관련 개념: JavaScript JSON, JavaScript JSON Data Types, JavaScript JSON Objects, JavaScript JSON Arrays
• 참조 맥락: The rules referenced whenever hand-writing or validating a JSON document.

📚 출처 (Sources)

• [S1] W3Schools — JSON Syntax — https://www.w3schools.com/js/js_json_syntax.asp

📝 변경 이력 (Change history)

• 2026-06-23: Initial draft synthesized from the W3Schools "JSON Syntax" page (Astra wiki-curation, P-Reinforce v3.1 format).