Enumeration (enum)

What is enum?

Enum is a way to group related constants together for management. Very useful in games for defining item types, character classes, game states, etc.

// Define item types
public enum ItemType { 
    Weapon,    // Weapon
    Armor,     // Armor
    Potion,    // Potion
    Key,       // Key
    Consumable // Consumable item
}

// Define character classes
public enum CharacterClass
{
    Warrior,   // Warrior
    Mage,      // Mage
    Archer,    // Archer
    Rogue      // Rogue
}

• Why use it?
  • Group related values in one place (cleaner code)
  • Prevent typos (use ItemType.Weapon instead of string "Weapon")
  • Selectable in Unity Inspector as a dropdown menu (intuitive)
  • Auto-completion support (IDE shows all options)
  • Type safety (prevents invalid value input)

Using enum

public class Item : MonoBehaviour
{
    public ItemType itemType;  // Selectable as dropdown in Inspector
    
    void Start()
    {
        // Apply different effects based on item type
        switch (itemType)
        {
            case ItemType.Weapon:
                Debug.Log("Obtained a weapon!");
                IncreaseAttackPower(10);
                break;
            case ItemType.Armor:
                Debug.Log("Obtained armor!");
                IncreaseDefense(5);
                break;
            case ItemType.Potion:
                Debug.Log("Drank a potion!");
                RestoreHealth(50);
                break;
        }
    }
    
    void IncreaseAttackPower(int amount) { }
    void IncreaseDefense(int amount) { }
    void RestoreHealth(int amount) { }
}

• Game development practical usage examples

Example 1: Item types

public enum ItemType { Weapon, Armor, Potion, Key, Consumable }

public class InventoryItem
{
    public ItemType type;
    public string name;
}

Example 2: Game states

public enum GameState { Menu, Playing, Paused, GameOver, Victory }

public class GameManager : MonoBehaviour
{
    public GameState currentState = GameState.Menu;
    
    void Update()
    {
        if (currentState == GameState.Playing)
        {
            // Gameplay logic
        }
    }
}

Example 3: Character classes

public enum CharacterClass { Warrior, Mage, Archer, Rogue }

public class Player : MonoBehaviour
{
    public CharacterClass playerClass;
    
    void Start()
    {
        switch (playerClass)
        {
            case CharacterClass.Warrior:
                baseAttack = 20;
                baseDefense = 15;
                break;
            case CharacterClass.Mage:
                baseAttack = 15;
                baseMana = 100;
                break;
        }
    }
}

Example 4: Enemy AI states

public enum EnemyState { Idle, Patrol, Chase, Attack, Dead }

public class Enemy : MonoBehaviour
{
    public EnemyState currentState = EnemyState.Idle;
}

Using in Unity Inspector

When you declare an enum as a public variable, it appears as a dropdown menu in the Unity Inspector.

How to use:

1. Declare public ItemType itemType; in script
2. Add script to GameObject in Unity editor
3. Select ItemType from dropdown menu in Inspector window
4. Can change value during gameplay (useful for debugging)

Actual example:

public class ItemPickup : MonoBehaviour
{
    public ItemType itemType = ItemType.Potion;  // Selectable in Inspector
    public int value = 10;
    
    void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("Player"))
        {
            ApplyItemEffect(itemType, value);
        }
    }
    
    void ApplyItemEffect(ItemType type, int val)
    {
        switch (type)
        {
            case ItemType.Potion:
                // Restore health
                break;
            case ItemType.Weapon:
                // Obtain weapon
                break;
        }
    }
}

Advantages:

• Can change values in Inspector without modifying code
• Prevents inputting wrong values
• Easy for game designers to use

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