2nd/10_Wiki/Topic_JavaScript/JavaScript_Bitwise.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
javascript-bitwise	JavaScript Bitwise	Frontend	draft	conceptual		bitwise operators bit manipulation AND OR XOR bit shift two's complement 32-bit operations		B	0.87	2026-06-23	2026-06-23			javascript js web frontend w3schools bitwise operators	https://www.w3schools.com/js/js_bitwise.asp

JavaScript Bitwise

🎯 한 줄 통찰 (One-line insight)

JavaScript bitwise operators work bit-by-bit on the binary representation of numbers — even though numbers are stored as 64-bit floats, every bitwise operation is performed on 32-bit binary numbers and returns a standard number. [S1]

🧠 핵심 개념 (Core concepts)

• Seven bitwise operators — AND (&), OR (|), XOR (^), NOT (~), zero fill left shift (<<), signed right shift (>>), and zero fill right shift (>>>). [S1]
• 64-bit storage, 32-bit operations — JavaScript stores numbers as 64-bit floating point numbers, but all bitwise operations are performed on 32-bit binary numbers. [S1]
• NOT and signed shift can produce negatives — ~5 returns -6, and -5 >> 1 returns -3, because of two's complement representation. [S1]
• Bitwise assignment operators — shift assignments (<<=, >>=, >>>=) and bitwise assignments (&=, ^=, |=) combine the operation with assignment. [S1]
• Base conversion via bitwise — decimal-to-binary and binary-to-decimal can be done with (dec >>> 0).toString(2) and parseInt(bin, 2).toString(10). [S1]

🧩 추출된 패턴 (Extracted patterns)

• Per-bit combination — &, |, ^ compare each pair of bits; ~ inverts every bit. [S1]
• Shift to multiply/divide by powers of two — 5 << 1 doubles to 10; 5 >>> 1 halves to 2. [S1]
• Unsigned coercion for printing — (dec >>> 0) forces an unsigned 32-bit view before .toString(2) to render binary. [S1]

📖 세부 내용 (Details)

Bitwise Operators — JavaScript provides seven bitwise operators: [S1]

Operator	Name	Description
&	AND	Sets each bit to 1 if both bits are 1
|	OR	Sets each bit to 1 if one of two bits is 1
^	XOR	Sets each bit to 1 if only one of two bits is 1
~	NOT	Inverts all the bits
<<	Zero fill left shift	Shifts left by pushing zeros in from the right and let the leftmost bits fall off
>>	Signed right shift	Shifts right by pushing copies of the leftmost bit in from the left, and let the rightmost bits fall off
>>>	Zero fill right shift	Shifts right by pushing zeros in from the left, and let the rightmost bits fall off

Note: JavaScript stores numbers as 64 bits floating point numbers, but all bitwise operations are performed on 32 bits binary numbers. [S1]

Bitwise AND — returns 1: [S1]

let x = 5 & 1;

Bitwise OR — returns 5: [S1]

let x = 5 | 1;

Bitwise XOR — returns 4: [S1]

let x = 5 ^ 1;

Bitwise NOT — returns -6: [S1]

let x = ~5;

Left Shift (<<) — returns 10: [S1]

let x = 5 << 1;

Signed Right Shift (>>) — returns -3: [S1]

let x = -5 >> 1;

Zero Fill Right Shift (>>>) — returns 2: [S1]

let x = 5 >>> 1;

Operator results summary (verbatim values from the page) [S1]

Expression	Result
5 & 1	1
5 | 1	5
5 ^ 1	4
~5	-6
5 << 1	10
-5 >> 1	-3
5 >>> 1	2

Bitwise assignment operators — the page documents shift assignment operators (<<=, >>=, >>>=) and bitwise assignment operators (&=, ^=, |=). [S1]

Converting Decimal to Binary [S1]

function dec2bin(dec){
  return (dec >>> 0).toString(2);
}

Converting Binary to Decimal [S1]

function bin2dec(bin){
  return parseInt(bin, 2).toString(10);
}

The page also includes binary-representation tables showing decimal values and their binary form, and two's-complement format for negative numbers. The exact full numeric contents of those tables were not captured verbatim in the fetched source rendering: Not found in source.

🛠️ 적용 사례 (Applied in summary)

The page's own snippets are the canonical applied examples — the seven single-operator demonstrations and the dec2bin / bin2dec conversion helpers. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Single bitwise operations (language: JavaScript):

let a = 5 & 1;   // 1
let b = 5 | 1;   // 5
let c = 5 ^ 1;   // 4
let d = ~5;      // -6
let e = 5 << 1;  // 10
let f = -5 >> 1; // -3
let g = 5 >>> 1; // 2

Base conversion helpers:

function dec2bin(dec){
  return (dec >>> 0).toString(2);
}
function bin2dec(bin){
  return parseInt(bin, 2).toString(10);
}

⚖️ 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: 0.87
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: JavaScript Tutorial
• 관련 개념: JavaScript Operators, JavaScript Numbers, JavaScript BigInt, JavaScript Number Properties
• 참조 맥락: Referenced when working with flags, masks, low-level math, or base conversions.

📚 출처 (Sources)

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

📝 변경 이력 (Change history)

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