Creating Arithmetic Functions

Addition, Subtraction, Multiplication, Division Functions

Arithmetic operations are needed in games for score calculation, health restoration, damage calculation, etc.

public class GameCalculator : MonoBehaviour
{
    // Health restoration (addition)
    int HealPlayer(int currentHp, int healAmount)
    {
        return currentHp + healAmount;  // Add
    }
    
    // Take damage (subtraction)
    int TakeDamage(int currentHp, int damage)
    {
        return currentHp - damage;  // Subtract
    }
    
    // Experience gain (multiplication - bonus multiplier)
    int GetExperienceWithBonus(int baseExp, int bonusMultiplier)
    {
        return baseExp * bonusMultiplier;  // Multiply
    }
    
    // Health percentage calculation (division)
    float GetHealthPercentage(int currentHp, int maxHp)
    {
        return (float)currentHp / maxHp;  // Divide (cast to float needed)
    }
}

Usage Example

public class Player : MonoBehaviour
{
    public int hp = 100;
    public int maxHp = 100;
    public int exp = 0;
    
    void Start()
    {
        // Restore health
        hp = HealPlayer(hp, 30);  // 100 + 30 = 130
        Debug.Log("Health: " + hp);
        
        // Take damage
        hp = TakeDamage(hp, 25);  // 130 - 25 = 105
        Debug.Log("Health: " + hp);
        
        // Experience bonus (2x)
        exp = GetExperienceWithBonus(50, 2);  // 50 * 2 = 100
        Debug.Log("Experience: " + exp);
        
        // Calculate health percentage
        float healthPercent = GetHealthPercentage(hp, maxHp);  // 105 / 100 = 1.05
        Debug.Log("Health percentage: " + (healthPercent * 100) + "%");
    }
}

Actual game usage:

public class CombatSystem : MonoBehaviour
{
    // Damage calculation (combining multiple factors)
    int CalculateDamage(int baseDamage, int weaponPower, float criticalMultiplier)
    {
        int total = baseDamage + weaponPower;  // Addition
        return Mathf.RoundToInt(total * criticalMultiplier);  // Multiplication
    }
    
    // Health restoration (with limit)
    int HealWithLimit(int currentHp, int healAmount, int maxHp)
    {
        int newHp = currentHp + healAmount;  // Addition
        if (newHp > maxHp)
        {
            return maxHp;  // Max limit
        }
        return newHp;
    }
}

Function Naming Tips

Function names should clearly indicate what they do. In Unity game development, use names that clearly express actions.

• ✅ Good examples:

  • CalculateDamage - Calculate damage
  • GetPlayerHP - Get player health
  • HealPlayer - Heal player
  • SpawnEnemy - Spawn enemy
  • CheckCollision - Check collision

• ❌ Bad examples:

  • func1, test, abc - Cannot tell what they do
  • DoSomething - Too vague
  • Calc - Avoid abbreviations

Naming rules:

• Start with a verb (Calculate, Get, Set, Check, Spawn, etc.)
• Use clear and specific names
• Not too long (recommended under 20 characters)

Function Writing Checklist

1. Function name: Does it clearly express the functionality?

   • Example: CalculateDamage ✅ vs Calc ❌

2. Parameters: Does it receive all necessary values?

   • Example: HealPlayer(int currentHp, int healAmount) ✅
   • Example: HealPlayer() - Don't know how much to heal ❌

3. Return value: Does it return the result properly?

   • Example: int GetPlayerLevel() { return level; } ✅
   • Example: void GetPlayerLevel() { Debug.Log(level); } - Doesn't return ❌

4. Reusability: Can it be used in other places?

   • Example: CalculateDamage(int base, int weapon) - Can use with various weapons ✅
   • Example: CalculateSwordDamage() - Only usable with sword ❌

Additional checklist for game development: 5. Error handling: Is there handling for invalid input? (division by zero, etc.) 6. Unity integration: Does it integrate well with Unity components? 7. Performance: Are there unnecessary calculations?

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