2nd/10_Wiki/Topic_JavaScript/JavaScript_Strings.md

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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-strings	JavaScript Strings	Frontend	draft	conceptual		strings JS strings string literals text values string length		B	0.89	2026-06-23	2026-06-23			javascript js web frontend w3schools strings quotes escape-characters	https://www.w3schools.com/js/js_strings.asp

JavaScript Strings

🎯 한 줄 통찰 (One-line insight)

A JavaScript string is zero or more characters written inside quotes — single, double, or backticks all work — and you measure it with .length, escape special characters with \, and should avoid wrapping strings in new String() objects. [S1]

🧠 핵심 개념 (Core concepts)

• A string is text in quotes — a JavaScript string is zero or more characters written inside quotes. [S1]
• Single or double quotes are equivalent — "Volvo XC60" and 'Volvo XC60' are the same. [S1]
• Quotes inside quotes — you can put quotes inside a string as long as the inner quotes differ from the outer ones. [S1]
• Template strings (ES6) — backtick-enclosed strings allow flexible use of both quote types and span multiple lines. [S1]
• .length — the length property returns the number of characters in a string. [S1]
• Escape character \ — the backslash escapes special characters so they can appear inside a string. [S1]
• Strings are primitives, not objects — new String() creates an object; the page warns not to create String objects because they complicate code and slow execution. [S1]

🧩 추출된 패턴 (Extracted patterns)

• Mix quote styles to embed quotes — choose an outer quote type different from the quote characters you need inside the text. [S1]
• Escape when you cannot switch quote types — use \", \', or \\ to embed the same quote/backslash literally. [S1]
• Break long lines after an operator — split a long statement by concatenating string pieces with +. [S1]
• Avoid new String() — keep strings as primitives so === comparisons behave intuitively. [S1]

📖 세부 내용 (Details)

Using Quotes A JavaScript string is zero or more characters written inside quotes. [S1]

let text = "John Doe";

You can use single or double quotes: [S1]

let carName1 = "Volvo XC60";  // Double quotes
let carName2 = 'Volvo XC60';  // Single quotes

Quotes Inside Quotes You can use quotes inside a string, as long as they don't match the quotes surrounding the string: [S1]

let answer1 = "It's alright";
let answer2 = "He is called 'Johnny'";
let answer3 = 'He is called "Johnny"';

Template Strings (ES6) Backtick-enclosed strings let you use both quote types freely inside the text: [S1]

let text = `He's often called "Johnny"`;

String Length To find the length of a string, use the built-in length property: [S1]

let text = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
let length = text.length;

Escape Characters Because strings are wrapped in quotes, JavaScript misunderstands a quote inside a string unless it is escaped with the backslash escape character. The escape character \ turns special characters into string characters. Escape sequences include \' (single quote), \" (double quote), \\ (backslash), and the control characters \b, \f, \n, \r, \t, \v. [S1]

Escaping a double quote inside a double-quoted string: [S1]

let text = "We are the so-called \"Vikings\" from the north.";

Escaping a single quote inside a single-quoted string: [S1]

let text = 'It\'s alright.';

Escaping a backslash: [S1]

let text = "The character \\ is called backslash.";

Breaking Long Code Lines The safest way to break a statement is after an operator, or to break a string with string concatenation: [S1]

document.getElementById("demo").innerHTML = "Hello " + "Dolly!";

Multiline Template Strings Template strings (backticks) allow multiline strings: [S1]

let text = `The quick
brown fox
jumps over
the lazy dog`;

JavaScript Strings as Objects Normally strings are primitive values created from literals (let x = "John";), but they can also be defined as objects with the new keyword (let y = new String("John");). [S1]

Warning: Do not create String objects. The new keyword complicates the code and slows down execution speed. [S1]

When comparing a primitive string with a String object, == (value comparison) returns true but === (value and type comparison) returns false, and comparing two String objects always returns false. [S1]

🛠️ 적용 사례 (Applied in summary)

The page's own snippets are the canonical applied examples — declaring strings with each quote style, mixing/escaping quotes, reading .length, concatenating to break long lines, and contrasting primitive strings with new String() objects. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Declare with either quote style:

let carName1 = "Volvo XC60";  // Double quotes
let carName2 = 'Volvo XC60';  // Single quotes

Escape special characters:

let text = "We are the so-called \"Vikings\" from the north.";

Measure length:

let text = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
let length = text.length;

⚖️ 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 String Templates, JavaScript String Methods, JavaScript String Search, JavaScript Data Types
• 참조 맥락: The foundation for all text handling in JavaScript, referenced before string methods, templates, and searching.

📚 출처 (Sources)

• [S1] W3Schools — JavaScript Strings — https://www.w3schools.com/js/js_strings.asp

📝 변경 이력 (Change history)

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