---
id: java-linkedhashmap
title: "Java LinkedHashMap"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["자바 LinkedHashMap"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.89
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["java", "programming", "w3schools", "collections-framework", "linkedhashmap"]
raw_sources: ["https://www.w3schools.com/java/java_linkedhashmap.asp"]
applied_in: []
github_commit: ""
---

# [[Java LinkedHashMap]]

## 🎯 한 줄 통찰 (One-line insight)
LinkedHashMap completes the exact same three-way pattern seen in the Set hierarchy (HashSet/TreeSet/LinkedHashSet) — HashMap (no order, fastest), TreeMap (sorted, slowest), LinkedHashMap (insertion order, middle ground) — showing Java's Collections Framework applies this identical order/speed trade-off symmetrically across both Set and Map implementations. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`LinkedHashMap`** — stores key-value pairs, preserving INSERTION order (not sorted order). [S1]
- **Same API as HashMap/TreeMap** — `put()`, `get()`, `remove()`, `clear()`, `size()`, `keySet()`, `values()`. [S1]
- **Duplicate key handling** — same as HashMap: re-putting an existing key overwrites its value silently. [S1]
- **Performance** — slightly slower than HashMap due to order tracking (same trade-off pattern as LinkedHashSet vs. HashSet). [S1]

## 📖 세부 내용 (Details)
- Insertion-order preservation: `LinkedHashMap<String, String> capitalCities = new LinkedHashMap<>(); capitalCities.put("England", "London"); capitalCities.put("India", "New Dehli"); ... // {England=London, India=New Dehli, Austria=Wien, Norway=Oslo, USA=Washington DC} — insertion order preserved`. [S1]
- Comparison table: HashMap (no order, faster random access) vs. LinkedHashMap (insertion order preserved, slightly slower). [S1]

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

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 입력된 순서 그대로 국가-수도 목록을 유지해야 할 때 LinkedHashMap이 적합하다. [S1]

## 💻 코드 패턴 (Code patterns)
LinkedHashMap preserves insertion order (Java):
```java
LinkedHashMap<String, String> capitalCities = new LinkedHashMap<>();
capitalCities.put("England", "London");
capitalCities.put("India", "New Dehli");
capitalCities.put("Austria", "Wien");
System.out.println(capitalCities);
// {England=London, India=New Dehli, Austria=Wien}
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.89
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[Java Tutorial]]
- **관련 개념:** [[Java HashMap]], [[Java TreeMap]], [[Java Iterator]]
- **참조 맥락:** Map 구현체의 마지막 — Iterator 챕터로 이어짐(모든 자료구조 공통 순회 도구).

## 📚 출처 (Sources)
- [S1] W3Schools — Java LinkedHashMap — https://www.w3schools.com/java/java_linkedhashmap.asp

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