---
id: java-nested-if
title: "Java Nested If"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["자바 중첩 조건문"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.87
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["java", "programming", "w3schools", "conditions", "nested-if"]
raw_sources: ["https://www.w3schools.com/java/java_conditions_nested.asp"]
applied_in: []
github_commit: ""
---

# [[Java Nested If]]

## 🎯 한 줄 통찰 (One-line insight)
A nested if only evaluates its inner condition once the outer condition is already true — this makes it functionally different from `&&` combined into one condition, since it lets each level print/branch independently (e.g., "old enough to vote" prints regardless of citizenship, but the vote permission itself depends on both). [S1]

## 🧠 핵심 개념 (Core concepts)
- **Nested if** — placing an if statement inside another if. [S1]
- **Purpose** — check a second condition only when the first is already true. [S1]
- **Depth caution** — the source explicitly warns against nesting too deep, as it can hurt readability. [S1]
- **Combines with else/else if** — nested if is often paired with else at each level for full decision trees. [S1]

## 📖 세부 내용 (Details)
- Basic nesting: `int x = 15; int y = 25; if (x > 10) { System.out.println("x is greater than 10"); if (y > 20) { System.out.println("y is also greater than 20"); } }`. [S1]
- Voting + citizenship real-life example: `int age = 20; boolean isCitizen = true; if (age >= 18) { System.out.println("Old enough to vote."); if (isCitizen) { System.out.println("And you are a citizen, so you can vote!"); } else { System.out.println("But you must be a citizen to vote."); } } else { System.out.println("Not old enough to vote."); }`. [S1]

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

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 서로 의존적인 여러 조건(나이+시민권 등)을 검사할 때 표준적으로 쓰인다. [S1]

## 💻 코드 패턴 (Code patterns)
Nested if with independent inner else (Java):
```java
int age = 20;
boolean isCitizen = true;
if (age >= 18) {
    System.out.println("Old enough to vote.");
    if (isCitizen) {
        System.out.println("And you are a citizen, so you can vote!");
    } else {
        System.out.println("But you must be a citizen to vote.");
    }
} else {
    System.out.println("Not old enough to vote.");
}
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.87
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[Java Tutorial]]
- **관련 개념:** [[Java If Else]], [[Java Conditions Logical Operators]], [[Java Conditions Real Life]]
- **참조 맥락:** 서로 의존적인 다중 조건 판단 — 논리 연산자(&&)와 함께 자주 결합됨.

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

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