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koriweb 9609c04755 docs(10_Wiki): W3Schools 위키화 — HTML/CSS/JavaScript(core)
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2026-06-23 19:21:18 +09:00

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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-operators JavaScript Operators Frontend draft conceptual
JS operators
JavaScript operator types
arithmetic operators
assignment operators
comparison operators
logical operators
concatenation operator
B 0.88 2026-06-23 2026-06-23
javascript
js
web
frontend
w3schools
operators
https://www.w3schools.com/js/js_operators.asp

JavaScript Operators

🎯 한 줄 통찰 (One-line insight)

JavaScript operators are used for mathematical and logical computations — the = assigns, + adds (and concatenates strings), * multiplies, and comparison/logical operators evaluate conditions. [S1]

🧠 핵심 개념 (Core concepts)

  • Operators are for mathematical and logical computations — they perform operations on values and variables. [S1]
  • Four core single examples — the assignment operator = assigns values, the addition operator + adds, the multiplication operator * multiplies, and the comparison operator > compares. [S1]
  • Operator categories — JavaScript operators include Arithmetic, Assignment, Comparison, Logical, and String operators. [S1]
  • + is overloaded — when used on strings, the + operator is called the concatenation operator; if you add a number and a string, the result is a string. [S1]
  • Comparisons return booleans — comparison operators always return true or false, and strings are compared alphabetically. [S1]

🧩 추출된 패턴 (Extracted patterns)

  • Compute into a new variable — combine two operands with an arithmetic operator and store the result: let z = x + y;. [S1]
  • Compound assignmentx += 5 is shorthand for x = x + 5. [S1]
  • Concatenate then assign — build a string with + and a separator: text1 + " " + text2. [S1]

📖 세부 내용 (Details)

Operators are for Mathematical and Logical Computations [S1] The assignment operator (=) assigns a value to a variable:

let x = 10;

The addition operator (+) adds values:

let x = 5;
let y = 2;
let z = x + y;

The multiplication operator (*) multiplies values:

let x = 5;
let y = 2;
let z = x * y;

A more complex expression mixing addition and multiplication: [S1]

let a = 3;
let x = (100 + 50) * a;

Types of JavaScript Operators [S1] There are different types of JavaScript operators: Arithmetic, Assignment, Comparison, String, Logical, and others.

JavaScript Arithmetic Operators [S1] Arithmetic operators are used to perform arithmetic on numbers:

Operator Description
+ Addition
- Subtraction
* Multiplication
** Exponentiation
/ Division
% Modulus (Division Remainder)
++ Increment
-- Decrement

JavaScript String Addition [S1] When used on strings, the + operator is called the concatenation operator:

let text1 = "John";
let text2 = "Doe";
let text3 = text1 + " " + text2;

The += assignment operator can also concatenate:

let text1 = "What a very ";
text1 += "nice day";

Adding Strings and Numbers [S1] If you add a number and a string, the result will be a string:

let x = 5 + 5;
let y = "5" + 5;
let z = "Hello" + 5;

JavaScript Assignment Operators [S1] Assignment operators assign values to JavaScript variables. For example, x += 5 is the same as x = x + 5:

let x = 10;
x += 5;
Operator Example Same As
= x = y x = y
+= x += y x = x + y
-= x -= y x = x - y
*= x *= y x = x * y
/= x /= y x = x / y
%= x %= y x = x % y
**= x **= y x = x ** y

JavaScript Comparison Operators [S1] Comparison operators always return true or false:

let x = 5;
let result = x > 8;
Operator Description Example
== equal to x == 5
=== equal value and equal type x === 5
!= not equal x != 5
!== not equal value or not equal type x !== 5
> greater than x > 5
< less than x < 5
>= greater than or equal to x >= 5
<= less than or equal to x <= 5

Strings are compared alphabetically: [S1]

let text1 = "A";
let text2 = "B";
let result = text1 < text2;

JavaScript Logical Operators [S1]

Operator Description
&& logical and
|| logical or
! logical not

🛠️ 적용 사례 (Applied in summary)

The page's own snippets are the canonical applied examples — assigning with =, computing with +/*, concatenating strings, compound-assigning with +=, and comparing values/strings. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Compute and store a result:

let x = 5;
let y = 2;
let z = x + y;

Concatenate strings with a separator:

let text3 = text1 + " " + text2;

Compound assignment:

let x = 10;
x += 5;

⚖️ 모순 및 업데이트 (Contradictions & updates)

No contradictions found in the source. The behavior that "5" + 5 yields a string ("55") rather than 10 is intentional, not a contradiction — + concatenates when a string operand is present.

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)

📚 출처 (Sources)

📝 변경 이력 (Change history)

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