---
id: csharp-constructors
title: "C# Constructors"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["default constructor C#", "constructor parameters C#", "C# 생성자"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.85
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["csharp", "programming-language", "w3schools", "oop", "constructors"]
raw_sources: ["https://www.w3schools.com/cs/cs_constructors.php"]
applied_in: []
github_commit: ""
---

# [[CSharp Constructors]]

## 🎯 한 줄 통찰 (One-line insight)
The "constructors save time" comparison at the end of this chapter directly rewrites the SAME Ford/Opel two-object example already shown across Class Members and Multiple Classes chapters — turning 8 lines of manual field assignment (`Ford.model = "Mustang"; Ford.color = "red"; Ford.year = 1969;` ×2) into 2 lines of parameterized construction (`new Car("Mustang", "Red", 1969)`), making constructors the payoff for a pattern this wiki has now seen written out the long way THREE times before finally being shown the short way — identical in spirit to C++'s constructor mechanism already covered in Topic_CPP, right down to the "name must match the class, no return type" rule and constructor overloading via differing parameter counts. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Constructor** — a special method that initializes an object; called automatically when an object of the class is created (`new Car()`). [S1]
- **Naming rule** — the constructor's name MUST match the class name exactly, and it CANNOT have a return type (no `void`, no `int`, nothing). [S1]
- **Default constructor** — every class has one even if you don't write it yourself; but the auto-generated one can't set initial field values the way a custom constructor can. [S1]
- **Constructor parameters** — a constructor can take parameters just like any method, used to set field values at creation time (`public Car(string modelName) { model = modelName; }`). [S1]
- **Multiple parameters** — a constructor can take as many parameters as needed, mapping each to a field. [S1]
- **Constructor overloading** — like ordinary methods, constructors can be overloaded with different parameter counts/types. [S1]

## 📖 세부 내용 (Details)
- Parameterless constructor setting a fixed value: `class Car { public string model; public Car() { model = "Mustang"; } static void Main(string[] args) { Car Ford = new Car(); Console.WriteLine(Ford.model); } }` → `"Mustang"`. [S1]
- Single-parameter constructor: `public Car(string modelName) { model = modelName; } ... Car Ford = new Car("Mustang");` → `"Mustang"`. [S1]
- Multi-parameter constructor: `public Car(string modelName, string modelColor, int modelYear) { model = modelName; color = modelColor; year = modelYear; } ... Car Ford = new Car("Mustang", "Red", 1969);` → `"Red 1969 Mustang"`. [S1]
- Before/after comparison: manual field-by-field assignment for `Ford` and `Opel` (8 lines) collapses to `Car Ford = new Car("Mustang", "Red", 1969); Car Opel = new Car("Astra", "White", 2005);` (2 lines) with a parameterized constructor. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **C++ 생성자 규칙과 동일**: 생성자 이름이 클래스명과 일치해야 하고 반환 타입을 가질 수 없다는 규칙, 그리고 매개변수 개수로 오버로딩할 수 있다는 규칙이 Topic_CPP의 Constructors/Constructors Overloading 챕터와 차이가 없다는 점이 확인됨. [S1]
- **이전 챕터들의 수동 필드 대입 패턴이 생성자로 압축됨**: Class Members와 Multiple Classes 챕터에서 반복적으로 보여준 "객체 생성 후 필드를 하나씩 대입"하는 8줄짜리 패턴이, 이번 챕터의 매개변수 생성자를 쓰면 2줄로 줄어든다는 것이 직접적인 비교로 확인됨. [S1]

## 🛠️ 적용 사례 (Applied in summary)
Ford와 Opel 두 Car 객체를 생성자 없이 필드별로 수동 대입하는 방식과, 3개 매개변수를 받는 생성자로 한 줄에 생성하는 방식을 나란히 비교하는 예제가 원문에서 직접 실전 활용 사례로 제시됨. [S1]

## 💻 코드 패턴 (Code patterns)
Manual field assignment vs. parameterized constructor — same result, less code (C#):
```csharp
// Without constructor
Car Ford = new Car();
Ford.model = "Mustang"; Ford.color = "red"; Ford.year = 1969;

// With constructor
class Car
{
    public string model, color;
    public int year;
    public Car(string modelName, string modelColor, int modelYear)
    {
        model = modelName; color = modelColor; year = modelYear;
    }
}
Car Ford2 = new Car("Mustang", "Red", 1969);
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.85
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[C# Tutorial]]
- **관련 개념:** [[CSharp Classes Multi]], [[CSharp Access Modifiers]], [[CPP Constructors]], [[CPP Constructors Overloading]]
- **참조 맥락:** Constructors 섹션의 유일 챕터 — Access Modifiers & Properties 섹션으로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — C# Constructors — https://www.w3schools.com/cs/cs_constructors.php

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