2nd/10_Wiki/Dev/Topic_PHP/PHP_Operators.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
php-operators	PHP Operators	Programming_Language	draft	conceptual		PHP 연산자		B	0.9	2026-07-04	2026-07-04			php programming w3schools operators	https://www.w3schools.com/php/php_operators.asp

PHP Operators

🎯 한 줄 통찰 (One-line insight)

PHP distinguishes == (equal) from === (identical) at the type level, not just the value level — $x === $y requires BOTH the value AND the data type to match, meaning 5 == "5" is true but 5 === "5" is false, a distinction that extends identically to array comparison operators too. [S1]

🧠 핵심 개념 (Core concepts)

• 8 operator groups — Arithmetic, Assignment, Comparison, Increment/Decrement, Logical, String, Array, Conditional. [S1]
• == vs === — equal (loose, value only) vs. identical (strict, value + type). [S1]
• <=> (spaceship, PHP 7+) — returns negative/zero/positive based on relative order. [S1]
• Pre vs. post increment — ++$x returns the NEW value; $x++ returns the OLD value, both then incrementing. [S1]
• String operators — . (concat), .= (concat-assign). [S1]
• Array operators — + (union), ==/=== (equality/identity with type-sensitivity difference). [S1]
• ?: (ternary) and ?? (null coalescing, PHP 7+) — conditional shorthand operators. [S1]

📖 세부 내용 (Details)

• Comparison table includes: ==, ===, !=, <>, !==, >, <, >=, <=, <=> (spaceship). [S1]
• Increment/decrement: ++$x (pre-increment: increments then returns), $x++ (post-increment: returns then increments). [S1]
• Logical operators: and/&&, or/||, xor, !. [S1]
• Null coalescing: $x = expr1 ?? expr2; — expr2 used if expr1 doesn't exist or is NULL. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

• == 와 ===의 차이: 값만 비교(==)하는 것과 값+타입을 모두 비교(===)하는 것이 배열 비교에도 동일하게 적용된다는 점이 명시됨. [S1]

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — null 병합 연산자(??)가 기본값 설정 로직에서 자주 쓰이는 실전 패턴이다. [S1]

💻 코드 패턴 (Code patterns)

Null coalescing operator for default values (PHP):

$x = $expr1 ?? "default value"; // uses $expr1 unless it's NULL/unset

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.90
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: PHP Tutorial
• 관련 개념: PHP If Else, PHP If Operators, PHP If Shorthand
• 참조 맥락: 모든 연산자의 개요 — 조건문(If Else) 챕터로 이어짐.

📚 출처 (Sources)

• [S1] W3Schools — PHP Operators — https://www.w3schools.com/php/php_operators.asp

📝 변경 이력 (Change history)

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