2nd/10_Wiki/Dev/Topic_C/C_Fixed_Width_Ints.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
c-fixed-width-ints	C Fixed Width Integers	Programming_Language	draft	conceptual		stdint.h int32_t uint8_t C 고정폭 정수		B	0.86	2026-07-04	2026-07-04			c programming-language w3schools fixed-width-integers stdint	https://www.w3schools.com/c/c_fixed_width_ints.php

C Fixed Width Integers

🎯 한 줄 통찰 (One-line insight)

The battery-level example makes the case concrete: since a percentage is always 0-100, using a plain int (likely 4 bytes) instead of uint8_t (exactly 1 byte) wastes 3 bytes per value for NO benefit — fixed-width types aren't just about portability, they're a deliberate memory-fit-to-range decision that a generic int habit obscures. [S1]

🧠 핵심 개념 (Core concepts)

• The portability problem — int, short, long sizes vary by system/compiler (e.g. int might be 2 bytes on one system, 4 on another). [S1]
• <stdint.h> fixed-width types — int8_t/uint8_t (1 byte), int16_t/uint16_t (2 bytes), int32_t/uint32_t (4 bytes), int64_t/uint64_t (8 bytes) — guaranteed identical size on every system. [S1]
• u prefix meaning — unsigned; doubles the maximum positive range compared to the signed version, at the cost of no negative values. [S1]
• When they matter — embedded/microcontroller systems, file formats requiring exact byte layouts, and network data exchange needing consistent results across machines. [S1]
• When they don't matter — for most everyday programs, a normal int is sufficient; fixed-width types are a deliberate choice for specific constraints, not a default habit. [S1]

📖 세부 내용 (Details)

• Declaring across all four sizes: int8_t a = 100; int16_t b = 30000; int32_t c = 2000000; int64_t d = 9000000000; printed with %d/%d/%d/%lld respectively. [S1]
• Battery-level real-life example: uint8_t battery = 87; printf("Battery level is %u out of 100\n", battery); — a value naturally bounded 0-255 fits exactly in 1 byte. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• 고정폭 타입은 일상 프로그래밍에는 불필요: 대부분의 프로그램에서는 일반 int로 충분하며, 고정폭 타입은 임베디드 시스템/파일 포맷/네트워크 통신처럼 정확한 크기가 중요한 특수 상황에서만 필요하다는 점이 명시됨. [S1]

🛠️ 적용 사례 (Applied in summary)

배터리 잔량(0-100%)처럼 값의 범위가 명확히 제한된 경우 uint8_t를 사용해 메모리를 절약하는 것이 실전 임베디드 프로그래밍의 대표 활용 사례로 원문에 직접 제시됨. [S1]

💻 코드 패턴 (Code patterns)

Using a 1-byte fixed-width type for a value with a known bounded range (C):

#include <stdio.h>
#include <stdint.h>
int main() {
  uint8_t battery = 87; // battery level percentage, fits in 1 byte
  printf("Battery level is %u out of 100\n", battery);
  return 0;
}

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.86
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: C Tutorial
• 관련 개념: C Storage Classes, C Data Types Extended, C Operators
• 참조 맥락: 상수 및 저장 클래스 섹션 마지막 — 연산자(Operators) 섹션으로 이어짐.

📚 출처 (Sources)

• [S1] W3Schools — C Fixed Width Integers — https://www.w3schools.com/c/c_fixed_width_ints.php

📝 변경 이력 (Change history)

• 2026-07-04: Initial draft synthesized from the W3Schools "C Fixed Width Integers" page (Astra wiki-curation, P-Reinforce v3.1 format).