Files
2nd/10_Wiki/Topic_Programming/Topic_JavaScript/JavaScript_Introduction.md
T
Antigravity Agent e9cbf23ab5 docs(10_Wiki): Dev 폴더 누락분 반영 — Topic_Programming으로 통합
이전 재구성 작업에서 Dev/ 폴더가 누락되었던 것을 반영.

- Dev/Topic_Programming(중첩 폴더, 78개)은 Dev 자체 최상위 폴더들
  (Architecture/Conventions/Engineering_Intelligence 등)과 완전 중복이라 제거.
- Dev 최상위 엔지니어링 지식 폴더(Architecture/Conventions/Engineering_Intelligence/
  Failure_Library/Generalized_Principles/Language/Pattern_Catalog/Platform_Guides/
  Subsystems, 77개)는 이미 Topic_Programming/Topic_Programming에 더 최신 버전이
  존재해 중복 제거(고유 콘텐츠 1개는 예외 처리하여 이동 보존).
- Dev의 W3Schools 언어 튜토리얼 폴더(Topic_C/CPP/CSS/CSharp/HOWTO/HTML/Java/
  JavaScript/PHP/Python/SQL/W3CSS, 1201개)는 전부 Topic_Programming 하위로 이동.
- 에이전트 운영 상태(.astra/docs)는 그대로 유지, 콘텐츠 폴더만 정리.
- Topic_Programming 최종 문서 수: 2784 → 3985.
2026-07-05 00:39:13 +09:00

5.6 KiB

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
javascript-introduction JavaScript Introduction Frontend draft conceptual
JavaScript
JS
JS intro
ECMAScript
client-side scripting
B 0.89 2026-06-23 2026-06-23
javascript
js
web
frontend
w3schools
https://www.w3schools.com/js/js_intro.asp

JavaScript Introduction

🎯 한 줄 통찰 (One-line insight)

JavaScript is the programming language of the web — it programs the behavior of web pages, able to read and dynamically change both HTML content and CSS styles. [S1]

🧠 핵심 개념 (Core concepts)

  • JavaScript is the programming language of the web — it lets you calculate, manipulate, and validate data, and update/change both HTML and CSS. [S1]
  • The three web layers — HTML defines the content, CSS specifies the layout, and JavaScript programs the behavior. [S1]
  • The DOM entry point — JavaScript reaches HTML elements through the document, most commonly with document.getElementById(), then reads/writes their content, attributes, and style. [S1]
  • Quotes are interchangeable — JavaScript accepts both single ' and double " quotes for strings. [S1]
  • Standardized — JavaScript became an ECMA standard in 1997; the official standard is ECMA-262 and the official language name is ECMAScript. [S1]

🧩 추출된 패턴 (Extracted patterns)

  • Select → mutate pattern — get a reference to an element (document.getElementById("id")), then assign to a property (.innerHTML, .style.*, an attribute) to change the page. [S1]
  • Style via .style object — CSS properties are set in JS using camelCase property names on element.style (e.g. fontSize, not font-size). [S1]
  • Show/hide via display — toggling style.display between "none" and "block" hides or reveals an element. [S1]

📖 세부 내용 (Details)

What is JavaScript? JavaScript is the programming language of the web. It can calculate, manipulate, and validate data, and it can update and change both HTML and CSS. [S1]

JavaScript, HTML and CSS The three layers of standard web technology: HTML to define the content of web pages, CSS to specify the layout of web pages, and JavaScript to program the behavior of web pages. [S1]

JavaScript Can Change HTML Content One of many JavaScript HTML methods is getElementById(). It finds an HTML element (by id) and changes the element content (innerHTML): [S1]

document.getElementById("demo").innerHTML = "Hello JavaScript";

JavaScript accepts both double and single quotes:

document.getElementById('demo').innerHTML = 'Hello JavaScript';

JavaScript Can Change HTML Attribute Values JavaScript can change attribute values dynamically — for example, changing the src (source) attribute of an <img> tag in response to user interaction (e.g. a light bulb turning on/off). [S1]

JavaScript Can Change HTML Styles (CSS) Changing the style of an HTML element is a variant of changing an HTML attribute: [S1]

document.getElementById("demo").style.fontSize = "35px";

JavaScript Can Hide HTML Elements Hiding HTML elements can be done by changing the display style: [S1]

document.getElementById("demo").style.display = "none";

JavaScript Can Show HTML Elements Showing hidden HTML elements can also be done by changing the display style: [S1]

document.getElementById("demo").style.display = "block";

Why study JavaScript? JavaScript is one of the three languages all web developers must learn, alongside HTML and CSS. [S1]

History JavaScript was invented by Brendan Eich in 1995 and became an ECMA standard in 1997. [S1]

🛠️ 적용 사례 (Applied in summary)

The page's own snippets are the canonical applied examples — selecting #demo and mutating its innerHTML, style.fontSize, and style.display. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Select an element and change its content (language: JavaScript):

document.getElementById("demo").innerHTML = "Hello JavaScript";

Change a style:

document.getElementById("demo").style.fontSize = "35px";

Hide / show:

document.getElementById("demo").style.display = "none";
document.getElementById("demo").style.display = "block";

⚖️ 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)

📚 출처 (Sources)

📝 변경 이력 (Change history)

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