---
id: php-string-concatenate
title: "PHP String Concatenate"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: [". operator", "PHP 문자열 연결"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.9
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["php", "programming", "w3schools", "strings", "concatenation"]
raw_sources: ["https://www.w3schools.com/php/php_string_concatenate.asp"]
applied_in: []
github_commit: ""
---

# [[PHP String Concatenate]]

## 🎯 한 줄 통찰 (One-line insight)
PHP's concatenation operator is `.` (a period), NOT `+` like many other languages — this is a common source of confusion for developers coming from JavaScript or Python, and joining two strings with `.` produces zero implicit spacing (`"Hello" . "World"` gives "HelloWorld", not "Hello World"). [S1]

## 🧠 핵심 개념 (Core concepts)
- **`.` operator** — concatenates (joins) two strings. [S1]
- **No implicit spacing** — `$x . $y` gives no space between values; must explicitly add `" "`. [S1]
- **Double-quote interpolation as an alternative** — `"$x $y"` embeds both variables with a literal space, avoiding the `.` operator entirely. [S1]

## 📖 세부 내용 (Details)
- Basic concat (no space): `$x = "Hello"; $y = "World"; $z = $x . $y; echo $z; // "HelloWorld"`. [S1]
- With explicit space: `$z = $x . " " . $y; echo $z; // "Hello World"`. [S1]
- Interpolation alternative: `$z = "$x $y"; echo $z; // "Hello World"`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
소스에서 모순되는 정보는 발견되지 않음.

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 큰따옴표 보간을 활용해 . 연산자 없이 두 변수를 결합하는 방식이 더 간결한 대안으로 제시된다. [S1]

## 💻 코드 패턴 (Code patterns)
Concatenation with explicit space vs. double-quote interpolation (PHP):
```php
$x = "Hello";
$y = "World";
$z = $x . " " . $y;  // "Hello World" via . operator
$z2 = "$x $y";        // "Hello World" via interpolation
```

## ✅ 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 Strings]], [[PHP String Modify]], [[PHP String Slicing]]
- **참조 맥락:** 문자열 결합 연산자 — 슬라이싱(Slicing) 챕터로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — PHP - Concatenate Strings — https://www.w3schools.com/php/php_string_concatenate.asp

## 📝 변경 이력 (Change history)
- 2026-07-04: Initial draft synthesized from the W3Schools "PHP - Concatenate Strings" page (Astra wiki-curation, P-Reinforce v3.1 format).