unity-coding-standards

name	unity-coding-standards
description	Unity C# coding standards and best practices reference. Use when writing MonoBehaviour scripts, creating C# classes, reviewing Unity code, or when user asks about naming conventions, component patterns, or code quality.

Unity C# Coding Standards

Naming Conventions

• Classes/Structs: PascalCase (PlayerController)
• Public methods/properties: PascalCase (TakeDamage())
• Private fields: _camelCase (_currentHealth)
• [SerializeField] private fields: _camelCase (_moveSpeed)
• Local variables/parameters: camelCase (hitPoint)
• Constants: UPPER_CASE (MAX_HEALTH)
• Interfaces: I-prefix PascalCase (IDamageable)
• Enums: PascalCase, singular (DamageType)

MonoBehaviour Patterns

public class ExampleComponent : MonoBehaviour
{
    [Header("Configuration")]
    [SerializeField] private float _moveSpeed = 5f;
    [SerializeField] private LayerMask _groundLayer;

    [Header("References")]
    [SerializeField] private Transform _groundCheck;

    private Rigidbody _rb;

    private void Awake()
    {
        _rb = GetComponent<Rigidbody>();
    }

    private void OnEnable() { /* Subscribe to events */ }
    private void OnDisable() { /* Unsubscribe from events */ }
}

Input (New Input System)

using UnityEngine.InputSystem;

// Mouse
if (Mouse.current != null && Mouse.current.leftButton.wasPressedThisFrame) { }
Vector2 mousePos = Mouse.current.position.ReadValue();

// Keyboard
if (Keyboard.current != null && Keyboard.current.spaceKey.wasPressedThisFrame) { }

旧 API (Input.GetKey, Input.mousePosition) は使用禁止。

Anti-Patterns to Avoid

• GameObject.Find() in Update — cache the reference
• GetComponent<T>() in Update — cache in Awake
• Camera.main in Update — cache the reference
• String comparison for tags — use CompareTag()
• new allocations in Update — use object pooling
• LINQ in hot paths — generates garbage

Assembly Definition Guidelines

• Separate runtime and editor code
• Define explicit references between assemblies
• Use Tests/Editor/*.asmdef and Tests/Runtime/*.asmdef

Examples

Good: Cached component access

private Rigidbody2D _rb;
private void Awake() => _rb = GetComponent<Rigidbody2D>();
private void FixedUpdate() => _rb.AddForce(Vector2.up * _jumpForce);

Bad: Uncached access in Update

private void Update()
{
    GetComponent<Rigidbody2D>().AddForce(Vector2.up); // GC alloc every frame
}