// Instantiate a prefab at runtime
[SerializeField] GameObject bulletPrefab;
 
void Fire() {
    GameObject bullet = Instantiate(bulletPrefab, firePoint.position, firePoint.rotation);
    // or with parent:
    Instantiate(bulletPrefab, firePoint.position, Quaternion.identity, transform);
}
 
// Destroy
Destroy(bullet);           // immediate
Destroy(bullet, 3f);       // after 3 seconds
Destroy(gameObject);       // destroy self

using UnityEngine;
 
public class PlayerController : MonoBehaviour
{
    // Inspector-exposed fields
    [SerializeField] float speed = 5f;
    [SerializeField] float jumpForce = 8f;
 
    // Component references
    Rigidbody rb;
    Animator anim;
 
    // Called once before first frame (before Start)
    void Awake() {
        rb   = GetComponent<Rigidbody>();
        anim = GetComponent<Animator>();
    }
 
    // Called once on first frame (after all Awakes)
    void Start() {
        Debug.Log("Player started: " + gameObject.name);
    }
 
    // Called every frame
    void Update() {
        HandleInput();
    }
 
    // Called every physics tick (fixed timestep, default 50/s)
    void FixedUpdate() {
        Move();
    }
 
    // Called after all Updates — good for camera follow
    void LateUpdate() {
        // camera logic here
    }
 
    // Called when GameObject is enabled
    void OnEnable()  { }
 
    // Called when GameObject is disabled or destroyed
    void OnDisable() { }
 
    // Called when GameObject is destroyed
    void OnDestroy() { }
 
    void HandleInput() { }
    void Move() { }
}

public class Example : MonoBehaviour
{
    // Show private field in Inspector
    [SerializeField] float speed = 5f;
 
    // Hide public field from Inspector
    [HideInInspector] public int hiddenValue;
 
    // Clamp slider in Inspector
    [Range(0f, 100f)] public float volume = 50f;
 
    // Multi-line text field
    [Multiline(5)] public string description;
 
    // Tooltip on hover
    [Tooltip("Movement speed in units/second")]
    public float moveSpeed = 3f;
 
    // Organize with headers and spaces
    [Header("Combat Settings")]
    public int damage = 10;
 
    [Space(10)]
    public int health = 100;
 
    // Require a component on the same GameObject
    [RequireComponent(typeof(Rigidbody))]
    // (put this above the class declaration)
 
    // Run in edit mode
    // [ExecuteInEditMode] or [ExecuteAlways]
}

// Get component on same GameObject (fast — use in Awake)
Rigidbody rb = GetComponent<Rigidbody>();
 
// Get component on child
Animator anim = GetComponentInChildren<Animator>();
 
// Get component on parent
Health hp = GetComponentInParent<Health>();
 
// Find by name (slow — avoid in Update)
GameObject player = GameObject.Find("Player");
 
// Find by tag (faster than Find)
GameObject enemy = GameObject.FindWithTag("Enemy");
GameObject[] enemies = GameObject.FindGameObjectsWithTag("Enemy");
 
// Find by type (slowest — scans all objects)
PlayerController pc = FindObjectOfType<PlayerController>();
PlayerController[] all = FindObjectsOfType<PlayerController>();
 
// Null check before use
if (rb != null) rb.AddForce(Vector3.up * 5f);
 
// TryGetComponent (no allocation on failure)
if (TryGetComponent<Rigidbody>(out Rigidbody body)) {
    body.AddForce(Vector3.up);
}

using UnityEngine;
using UnityEngine.InputSystem;
 
public class PlayerInput : MonoBehaviour
{
    PlayerControls controls; // generated C# class
    Vector2 moveInput;
 
    void Awake() {
        controls = new PlayerControls();
    }
 
    void OnEnable() {
        controls.Player.Enable();
        controls.Player.Move.performed += OnMove;
        controls.Player.Move.canceled  += OnMove;
        controls.Player.Jump.performed += OnJump;
    }
 
    void OnDisable() {
        controls.Player.Move.performed -= OnMove;
        controls.Player.Move.canceled  -= OnMove;
        controls.Player.Jump.performed -= OnJump;
        controls.Player.Disable();
    }
 
    void OnMove(InputAction.CallbackContext ctx) {
        moveInput = ctx.ReadValue<Vector2>();
    }
 
    void OnJump(InputAction.CallbackContext ctx) {
        Jump();
    }
 
    void Update() {
        transform.Translate(new Vector3(moveInput.x, 0, moveInput.y) * 5f * Time.deltaTime);
    }
 
    void Jump() { Debug.Log("Jump!"); }
}

void Update() {
    // Axes (smooth, -1 to 1)
    float h = Input.GetAxis("Horizontal");   // A/D or Left/Right
    float v = Input.GetAxis("Vertical");     // W/S or Up/Down
    float mouse_x = Input.GetAxis("Mouse X");
    float mouse_y = Input.GetAxis("Mouse Y");
 
    // Raw axes (no smoothing, -1, 0, or 1)
    float hRaw = Input.GetAxisRaw("Horizontal");
 
    // Keys
    if (Input.GetKeyDown(KeyCode.Space))  Jump();    // pressed this frame
    if (Input.GetKey(KeyCode.LeftShift))  Sprint();  // held down
    if (Input.GetKeyUp(KeyCode.Space))    Land();    // released this frame
 
    // Mouse buttons (0=left, 1=right, 2=middle)
    if (Input.GetMouseButtonDown(0)) Shoot();
    Vector3 mousePos = Input.mousePosition;
 
    // Buttons (defined in Edit → Project Settings → Input Manager)
    if (Input.GetButtonDown("Fire1")) Shoot();
    if (Input.GetButton("Jump"))      HoldJump();
}

public class PhysicsExample : MonoBehaviour
{
    Rigidbody rb;
 
    void Awake() => rb = GetComponent<Rigidbody>();
 
    void FixedUpdate() {
        // Move with physics (use in FixedUpdate)
        rb.MovePosition(rb.position + Vector3.forward * 5f * Time.fixedDeltaTime);
 
        // Apply force
        rb.AddForce(Vector3.forward * 10f);                    // continuous
        rb.AddForce(Vector3.up * 500f, ForceMode.Impulse);     // instant
        rb.AddForce(Vector3.right * 5f, ForceMode.VelocityChange); // ignore mass
 
        // Apply torque (rotation force)
        rb.AddTorque(Vector3.up * 10f);
 
        // Direct velocity (use sparingly)
        rb.linearVelocity = new Vector3(0, rb.linearVelocity.y, 0);
    }
 
    void Start() {
        rb.mass = 2f;
        rb.linearDamping = 0.5f;       // air resistance
        rb.angularDamping = 0.05f;
        rb.useGravity = true;
        rb.isKinematic = false;         // true = moved by script, not physics
        rb.constraints = RigidbodyConstraints.FreezeRotationX
                       | RigidbodyConstraints.FreezeRotationZ;
    }
}

// 3D Collision (requires Rigidbody + Collider, isTrigger = false)
void OnCollisionEnter(Collision col) {
    Debug.Log("Hit: " + col.gameObject.name);
    Debug.Log("Impact point: " + col.contacts[0].point);
    Debug.Log("Impact force: " + col.impulse.magnitude);
 
    if (col.gameObject.CompareTag("Enemy")) {
        TakeDamage(10);
    }
}
void OnCollisionStay(Collision col)  { /* held contact */ }
void OnCollisionExit(Collision col)  { /* contact ended */ }
 
// 3D Trigger (isTrigger = true on collider)
void OnTriggerEnter(Collider other) {
    if (other.CompareTag("Pickup")) {
        Collect(other.gameObject);
        Destroy(other.gameObject);
    }
}
void OnTriggerStay(Collider other)  { }
void OnTriggerExit(Collider other)  { }
 
// 2D versions
void OnCollisionEnter2D(Collision2D col) { }
void OnTriggerEnter2D(Collider2D other)  { }

void ShootRay() {
    Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
    // or: Ray ray = new Ray(transform.position, transform.forward);
 
    RaycastHit hit;
    float maxDist = 100f;
    int layerMask = LayerMask.GetMask("Enemy", "Ground");
 
    if (Physics.Raycast(ray, out hit, maxDist, layerMask)) {
        Debug.Log("Hit: " + hit.collider.name);
        Debug.Log("Point: " + hit.point);
        Debug.Log("Normal: " + hit.normal);
        Debug.Log("Distance: " + hit.distance);
 
        // Draw debug ray in Scene view
        Debug.DrawRay(ray.origin, ray.direction * hit.distance, Color.red, 1f);
    }
 
    // All hits (sorted by distance)
    RaycastHit[] hits = Physics.RaycastAll(ray, maxDist, layerMask);
 
    // Sphere cast
    if (Physics.SphereCast(transform.position, 0.5f, transform.forward, out hit, 10f)) { }
 
    // Overlap sphere (returns all colliders in radius)
    Collider[] nearby = Physics.OverlapSphere(transform.position, 5f, layerMask);
    foreach (var col in nearby) Debug.Log(col.name);
 
    // 2D raycast
    RaycastHit2D hit2D = Physics2D.Raycast(transform.position, Vector2.right, 10f);
    if (hit2D.collider != null) Debug.Log(hit2D.collider.name);
}

public class CharacterMove : MonoBehaviour
{
    CharacterController cc;
    float gravity = -9.81f;
    float verticalVelocity;
 
    void Awake() => cc = GetComponent<CharacterController>();
 
    void Update() {
        // Gravity
        if (cc.isGrounded && verticalVelocity < 0)
            verticalVelocity = -2f;
        verticalVelocity += gravity * Time.deltaTime;
 
        // Jump
        if (Input.GetButtonDown("Jump") && cc.isGrounded)
            verticalVelocity = Mathf.Sqrt(4f * -2f * gravity);
 
        // Move
        float h = Input.GetAxis("Horizontal");
        float v = Input.GetAxis("Vertical");
        Vector3 move = transform.right * h + transform.forward * v;
        move.y = verticalVelocity;
 
        cc.Move(move * 5f * Time.deltaTime);
    }
}

public class Player2D : MonoBehaviour
{
    [SerializeField] float speed = 5f;
    [SerializeField] float jumpForce = 10f;
    Rigidbody2D rb;
    bool isGrounded;
 
    void Awake() => rb = GetComponent<Rigidbody2D>();
 
    void Update() {
        float h = Input.GetAxisRaw("Horizontal");
        rb.linearVelocity = new Vector2(h * speed, rb.linearVelocity.y);
 
        if (Input.GetButtonDown("Jump") && isGrounded)
            rb.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);
    }
 
    void OnCollisionEnter2D(Collision2D col) {
        if (col.gameObject.CompareTag("Ground")) isGrounded = true;
    }
    void OnCollisionExit2D(Collision2D col) {
        if (col.gameObject.CompareTag("Ground")) isGrounded = false;
    }
}

SpriteRenderer sr = GetComponent<SpriteRenderer>();
 
// Flip sprite
sr.flipX = true;
sr.flipY = false;
 
// Change sprite
sr.sprite = Resources.Load<Sprite>("Sprites/player_jump");
 
// Change color / transparency
sr.color = Color.red;
sr.color = new Color(1f, 1f, 1f, 0.5f); // 50% transparent
 
// Sorting order (higher = drawn on top)
sr.sortingOrder = 5;
sr.sortingLayerName = "Player";

using UnityEngine.Tilemaps;
 
Tilemap tilemap = GetComponent<Tilemap>();
 
// Get tile at position
Vector3Int cellPos = tilemap.WorldToCell(transform.position);
TileBase tile = tilemap.GetTile(cellPos);
 
// Set tile
tilemap.SetTile(new Vector3Int(3, 2, 0), myTile);
 
// Remove tile
tilemap.SetTile(cellPos, null);
 
// Convert world ↔ cell
Vector3Int cell = tilemap.WorldToCell(worldPos);
Vector3 world = tilemap.CellToWorld(cell);

public class CameraFollow : MonoBehaviour
{
    [SerializeField] Transform target;
    [SerializeField] float smoothSpeed = 5f;
    [SerializeField] Vector3 offset = new Vector3(0, 2, -10);
 
    void LateUpdate() {
        Vector3 desired = target.position + offset;
        transform.position = Vector3.Lerp(transform.position, desired,
            smoothSpeed * Time.deltaTime);
    }
}

// Position
transform.position = new Vector3(0, 1, 5);
transform.localPosition = Vector3.zero;       // relative to parent
transform.Translate(Vector3.forward * 5f * Time.deltaTime); // move relative to self
transform.Translate(Vector3.forward * 5f, Space.World);     // move in world space
 
// Rotation
transform.rotation = Quaternion.identity;
transform.eulerAngles = new Vector3(0, 90, 0);
transform.Rotate(Vector3.up, 90f);            // rotate around axis
transform.LookAt(target.position);            // face a target
 
// Smooth rotation
Quaternion targetRot = Quaternion.LookRotation(direction);
transform.rotation = Quaternion.Slerp(transform.rotation, targetRot, 5f * Time.deltaTime);
 
// Scale
transform.localScale = new Vector3(2f, 2f, 2f);
 
// Parent / Child
transform.SetParent(parentTransform);
transform.SetParent(null);                    // detach from parent
int childCount = transform.childCount;
Transform child = transform.GetChild(0);

Vector3 a = new Vector3(1, 0, 0);
Vector3 b = new Vector3(0, 1, 0);
 
// Operations
Vector3 sum  = a + b;
Vector3 diff = a - b;
Vector3 scaled = a * 3f;
 
// Magnitude & normalization
float mag  = a.magnitude;          // length
float mag2 = a.sqrMagnitude;       // faster (no sqrt)
Vector3 norm = a.normalized;       // unit vector
 
// Dot & cross product
float dot   = Vector3.Dot(a, b);   // 0 = perpendicular, 1 = parallel
Vector3 cross = Vector3.Cross(a, b); // perpendicular to both
 
// Distance
float dist = Vector3.Distance(a, b);
 
// Interpolation
Vector3 lerped = Vector3.Lerp(a, b, 0.5f);       // linear
Vector3 slerped = Vector3.Slerp(a, b, 0.5f);     // spherical (for directions)
Vector3 moved = Vector3.MoveTowards(a, b, 0.1f); // move by max delta
 
// Useful constants
Vector3.zero    // (0, 0, 0)
Vector3.one     // (1, 1, 1)
Vector3.up      // (0, 1, 0)
Vector3.forward // (0, 0, 1)
Vector3.right   // (1, 0, 0)

public class FPSController : MonoBehaviour
{
    [SerializeField] float moveSpeed = 5f;
    [SerializeField] float mouseSensitivity = 2f;
    [SerializeField] Transform cameraTransform;
 
    CharacterController cc;
    float xRotation;
    float verticalVelocity;
    float gravity = -9.81f;
 
    void Awake() {
        cc = GetComponent<CharacterController>();
        Cursor.lockState = CursorLockMode.Locked;
    }
 
    void Update() {
        // Mouse look
        float mouseX = Input.GetAxis("Mouse X") * mouseSensitivity;
        float mouseY = Input.GetAxis("Mouse Y") * mouseSensitivity;
        xRotation -= mouseY;
        xRotation = Mathf.Clamp(xRotation, -90f, 90f);
        cameraTransform.localRotation = Quaternion.Euler(xRotation, 0, 0);
        transform.Rotate(Vector3.up * mouseX);
 
        // Movement
        float h = Input.GetAxis("Horizontal");
        float v = Input.GetAxis("Vertical");
        Vector3 move = transform.right * h + transform.forward * v;
 
        // Gravity
        if (cc.isGrounded && verticalVelocity < 0) verticalVelocity = -2f;
        if (Input.GetButtonDown("Jump") && cc.isGrounded)
            verticalVelocity = Mathf.Sqrt(4f * -2f * gravity);
        verticalVelocity += gravity * Time.deltaTime;
        move.y = verticalVelocity;
 
        cc.Move(move * moveSpeed * Time.deltaTime);
    }
}

Animator anim = GetComponent<Animator>();
 
// Set parameters
anim.SetFloat("Speed", rb.linearVelocity.magnitude);
anim.SetBool("IsGrounded", isGrounded);
anim.SetTrigger("Jump");       // one-shot trigger
anim.ResetTrigger("Jump");     // cancel trigger
anim.SetInteger("State", 2);
 
// Get parameters
float speed = anim.GetFloat("Speed");
bool grounded = anim.GetBool("IsGrounded");
 
// Play state directly
anim.Play("Run");
anim.Play("Attack", 0, 0f);   // (state, layer, normalizedTime)
 
// Cross-fade
anim.CrossFade("Walk", 0.2f); // blend over 0.2 seconds
 
// Check current state
AnimatorStateInfo info = anim.GetCurrentAnimatorStateInfo(0);
if (info.IsName("Attack")) { }
if (info.normalizedTime >= 1f) { /* animation finished */ }

// Add event in Animation window at a specific frame
// Function must be on a MonoBehaviour on the same GameObject
 
void OnFootstep() {
    AudioSource.PlayClipAtPoint(footstepClip, transform.position);
}
 
void OnAttackHit() {
    // Enable hitbox at this frame
    hitbox.enabled = true;
}

// Apply Root Motion — animator moves the character via animation curves
// Enable "Apply Root Motion" on Animator component
 
// Override root motion in script
void OnAnimatorMove() {
    Vector3 velocity = anim.deltaPosition / Time.deltaTime;
    cc.Move(anim.deltaPosition);
}

using UnityEngine.UI;
using TMPro;
 
// Text (TextMeshPro — recommended)
TextMeshProUGUI label = GetComponent<TextMeshProUGUI>();
label.text = "Score: " + score;
label.color = Color.yellow;
label.fontSize = 24;
 
// Image
Image img = GetComponent<Image>();
img.sprite = mySprite;
img.color = new Color(1, 1, 1, 0.8f);
img.fillAmount = 0.75f;  // for radial health bars (Image Type = Filled)
 
// Button
Button btn = GetComponent<Button>();
btn.onClick.AddListener(OnButtonClicked);
btn.onClick.AddListener(() => Debug.Log("Clicked!"));
btn.interactable = false;
 
// Slider
Slider slider = GetComponent<Slider>();
slider.value = 0.5f;
slider.minValue = 0f;
slider.maxValue = 100f;
slider.onValueChanged.AddListener(OnSliderChanged);
 
// Toggle
Toggle toggle = GetComponent<Toggle>();
toggle.isOn = true;
toggle.onValueChanged.AddListener(OnToggleChanged);
 
// InputField (TMP)
TMP_InputField input = GetComponent<TMP_InputField>();
string text = input.text;
input.onEndEdit.AddListener(OnInputSubmit);

public class HUDManager : MonoBehaviour
{
    [SerializeField] Slider healthBar;
    [SerializeField] TextMeshProUGUI scoreText;
    [SerializeField] TextMeshProUGUI ammoText;
    [SerializeField] GameObject gameOverPanel;
 
    public void UpdateHealth(float current, float max) {
        healthBar.value = current / max;
    }
 
    public void UpdateScore(int score) {
        scoreText.text = $"Score: {score:N0}";
    }
 
    public void UpdateAmmo(int current, int reserve) {
        ammoText.text = $"{current} / {reserve}";
    }
 
    public void ShowGameOver() {
        gameOverPanel.SetActive(true);
        Time.timeScale = 0f; // pause game
    }
}

public class AudioManager : MonoBehaviour
{
    [SerializeField] AudioSource musicSource;
    [SerializeField] AudioSource sfxSource;
    [SerializeField] AudioClip jumpClip;
    [SerializeField] AudioClip shootClip;
 
    void Start() {
        musicSource.loop = true;
        musicSource.volume = 0.5f;
        musicSource.Play();
    }
 
    public void PlayJump() {
        sfxSource.PlayOneShot(jumpClip);          // doesn't interrupt
    }
 
    public void PlayShoot() {
        sfxSource.PlayOneShot(shootClip, 0.8f);   // with volume scale
    }
 
    // Play at world position (fire and forget)
    public void PlayAt(AudioClip clip, Vector3 pos) {
        AudioSource.PlayClipAtPoint(clip, pos, 1f);
    }
 
    // Randomize pitch for variation
    public void PlayWithVariation(AudioClip clip) {
        sfxSource.pitch = Random.Range(0.9f, 1.1f);
        sfxSource.PlayOneShot(clip);
    }
}

using UnityEngine.Audio;
 
[SerializeField] AudioMixer mixer;
 
// Set volume (exposed parameter in Mixer)
// Note: AudioMixer uses dB — convert from 0-1 slider
public void SetMusicVolume(float sliderValue) {
    float dB = Mathf.Log10(Mathf.Max(sliderValue, 0.0001f)) * 20f;
    mixer.SetFloat("MusicVolume", dB);
}
 
// Mute
mixer.SetFloat("SFXVolume", -80f);  // -80dB = silent
 
// Snapshot transition
AudioMixerSnapshot snapshot = mixer.FindSnapshot("Underwater");
snapshot.TransitionTo(0.5f); // blend over 0.5 seconds

using UnityEngine.SceneManagement;
 
// Load scene (destroys current)
SceneManager.LoadScene("MainMenu");
SceneManager.LoadScene(1);              // by build index
 
// Reload current scene
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
 
// Additive load (keep current scene)
SceneManager.LoadScene("HUD", LoadSceneMode.Additive);
 
// Async load (show loading screen)
IEnumerator LoadAsync(string sceneName) {
    AsyncOperation op = SceneManager.LoadSceneAsync(sceneName);
    op.allowSceneActivation = false;
 
    while (!op.isDone) {
        float progress = Mathf.Clamp01(op.progress / 0.9f); // 0-1
        loadingBar.fillAmount = progress;
 
        if (op.progress >= 0.9f) {
            // Scene ready — wait for input or auto-activate
            op.allowSceneActivation = true;
        }
        yield return null;
    }
}
 
// Unload additive scene
SceneManager.UnloadSceneAsync("HUD");
 
// Don't destroy on load (persist across scenes)
DontDestroyOnLoad(gameObject);

public class GameManager : MonoBehaviour
{
    public static GameManager Instance { get; private set; }
 
    public int Score { get; private set; }
    public int Lives { get; private set; } = 3;
 
    void Awake() {
        if (Instance != null && Instance != this) {
            Destroy(gameObject);
            return;
        }
        Instance = this;
        DontDestroyOnLoad(gameObject);
    }
 
    public void AddScore(int points) {
        Score += points;
        OnScoreChanged?.Invoke(Score);
    }
 
    public event System.Action<int> OnScoreChanged;
}
 
// Access from anywhere
GameManager.Instance.AddScore(100);

// Start / Stop
StartCoroutine(MyRoutine());
Coroutine c = StartCoroutine(MyRoutine());
StopCoroutine(c);
StopAllCoroutines();
 
// Basic coroutine
IEnumerator MyRoutine() {
    Debug.Log("Start");
    yield return new WaitForSeconds(2f);    // wait 2 seconds
    Debug.Log("After 2 seconds");
    yield return null;                       // wait one frame
    yield return new WaitForFixedUpdate();  // wait for FixedUpdate
    yield return new WaitForEndOfFrame();   // wait for end of frame
    Debug.Log("Done");
}
 
// Wait until condition
IEnumerator WaitForDoor() {
    yield return new WaitUntil(() => door.isOpen);
    EnterRoom();
}
 
// Wait while condition
IEnumerator WaitWhileLoading() {
    yield return new WaitWhile(() => isLoading);
    ShowMenu();
}
 
// Fade out example
IEnumerator FadeOut(float duration) {
    float elapsed = 0f;
    Color startColor = spriteRenderer.color;
 
    while (elapsed < duration) {
        elapsed += Time.deltaTime;
        float alpha = 1f - (elapsed / duration);
        spriteRenderer.color = new Color(startColor.r, startColor.g, startColor.b, alpha);
        yield return null;
    }
 
    spriteRenderer.color = new Color(startColor.r, startColor.g, startColor.b, 0f);
    gameObject.SetActive(false);
}

using UnityEngine.Pool;
 
public class BulletPool : MonoBehaviour
{
    [SerializeField] GameObject bulletPrefab;
    IObjectPool<GameObject> pool;
 
    void Awake() {
        pool = new ObjectPool<GameObject>(
            createFunc:    () => Instantiate(bulletPrefab),
            actionOnGet:   obj => obj.SetActive(true),
            actionOnRelease: obj => obj.SetActive(false),
            actionOnDestroy: obj => Destroy(obj),
            collectionCheck: false,
            defaultCapacity: 20,
            maxSize: 100
        );
    }
 
    public GameObject Get() => pool.Get();
    public void Release(GameObject obj) => pool.Release(obj);
}
 
// Bullet.cs — return to pool when done
public class Bullet : MonoBehaviour
{
    BulletPool pool;
 
    public void Init(BulletPool p) => pool = p;
 
    void OnTriggerEnter(Collider other) {
        pool.Release(gameObject);
    }
}

// Save
PlayerPrefs.SetInt("HighScore", 9999);
PlayerPrefs.SetFloat("Volume", 0.8f);
PlayerPrefs.SetString("PlayerName", "Alice");
PlayerPrefs.Save(); // flush to disk
 
// Load
int score = PlayerPrefs.GetInt("HighScore", 0);       // 0 = default
float vol = PlayerPrefs.GetFloat("Volume", 1f);
string name = PlayerPrefs.GetString("PlayerName", "Player");
 
// Check & Delete
if (PlayerPrefs.HasKey("HighScore")) { }
PlayerPrefs.DeleteKey("HighScore");
PlayerPrefs.DeleteAll();

using System.IO;
 
[System.Serializable]
public class SaveData {
    public int score;
    public int level;
    public float[] playerPosition;
    public List<string> unlockedItems;
}
 
public static class SaveSystem
{
    static string SavePath => Application.persistentDataPath + "/save.json";
 
    public static void Save(SaveData data) {
        string json = JsonUtility.ToJson(data, prettyPrint: true);
        File.WriteAllText(SavePath, json);
        Debug.Log("Saved to: " + SavePath);
    }
 
    public static SaveData Load() {
        if (!File.Exists(SavePath)) return new SaveData();
        string json = File.ReadAllText(SavePath);
        return JsonUtility.FromJson<SaveData>(json);
    }
 
    public static void Delete() {
        if (File.Exists(SavePath)) File.Delete(SavePath);
    }
}
 
// Usage
var data = new SaveData { score = 500, level = 3 };
SaveSystem.Save(data);
SaveData loaded = SaveSystem.Load();

using UnityEngine.AI;
 
public class EnemyAI : MonoBehaviour
{
    NavMeshAgent agent;
    Transform player;
    [SerializeField] float detectionRange = 10f;
    [SerializeField] float attackRange = 2f;
 
    void Awake() {
        agent = GetComponent<NavMeshAgent>();
        player = GameObject.FindWithTag("Player").transform;
    }
 
    void Update() {
        float dist = Vector3.Distance(transform.position, player.position);
 
        if (dist <= attackRange) {
            agent.isStopped = true;
            Attack();
        } else if (dist <= detectionRange) {
            agent.isStopped = false;
            agent.SetDestination(player.position);
        } else {
            agent.isStopped = true;
        }
    }
 
    void Attack() { /* attack logic */ }
}
 
// NavMesh setup:
// 1. Mark static geometry as Navigation Static
// 2. Window → AI → Navigation → Bake
// 3. Add NavMeshAgent component to enemy
 
// NavMesh query
NavMeshHit hit;
if (NavMesh.SamplePosition(randomPos, out hit, 5f, NavMesh.AllAreas)) {
    agent.SetDestination(hit.position);
}

// Change material properties per-instance without creating new materials
MaterialPropertyBlock mpb = new MaterialPropertyBlock();
Renderer rend = GetComponent<Renderer>();
 
// Set properties
mpb.SetColor("_BaseColor", Color.red);
mpb.SetFloat("_Metallic", 0.8f);
mpb.SetTexture("_BaseMap", myTexture);
rend.SetPropertyBlock(mpb);
 
// Clear
rend.SetPropertyBlock(null);

using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;
 
Volume volume;
Bloom bloom;
 
void Start() {
    volume = GetComponent<Volume>();
    volume.profile.TryGet(out bloom);
}
 
void Update() {
    // Pulse bloom on hit
    bloom.intensity.value = Mathf.PingPong(Time.time, 2f);
}

// Console logs
Debug.Log("Info message");
Debug.LogWarning("Warning: " + value);
Debug.LogError("Error: " + error);
Debug.LogFormat("Player pos: {0}", transform.position);
 
// Conditional (only in editor/development builds)
Debug.Assert(health > 0, "Health must be positive!");
 
// Visual debug in Scene view
Debug.DrawLine(start, end, Color.red, 2f);           // duration 2s
Debug.DrawRay(transform.position, Vector3.up * 5f, Color.green);
 
// Gizmos (visible in Scene view, not Game view)
void OnDrawGizmos() {
    Gizmos.color = Color.yellow;
    Gizmos.DrawWireSphere(transform.position, detectionRange);
    Gizmos.DrawLine(transform.position, target.position);
}
 
void OnDrawGizmosSelected() {
    // Only when this object is selected
    Gizmos.color = Color.red;
    Gizmos.DrawWireCube(transform.position, Vector3.one);
}

using Unity.Profiling;
 
static readonly ProfilerMarker s_MyMarker = new ProfilerMarker("MySystem.Update");
 
void Update() {
    s_MyMarker.Begin();
    // expensive code here
    s_MyMarker.End();
}

// C# event pattern — decoupled communication
public class Health : MonoBehaviour
{
    public event System.Action<int> OnDamaged;
    public event System.Action OnDeath;
    public event System.Action<int, int> OnHealthChanged; // current, max
 
    int current = 100;
    int max = 100;
 
    public void TakeDamage(int amount) {
        current = Mathf.Max(0, current - amount);
        OnDamaged?.Invoke(amount);
        OnHealthChanged?.Invoke(current, max);
        if (current == 0) OnDeath?.Invoke();
    }
}
 
// Subscribe
health.OnDeath += HandleDeath;
health.OnHealthChanged += (cur, max) => healthBar.value = (float)cur / max;
 
// Unsubscribe (important — prevents memory leaks)
void OnDestroy() {
    health.OnDeath -= HandleDeath;
}

// ScriptableObject — data asset, not attached to a GameObject
// Great for: item stats, enemy configs, game settings, shared events
 
[CreateAssetMenu(fileName = "NewWeapon", menuName = "Game/Weapon")]
public class WeaponData : ScriptableObject
{
    public string weaponName;
    public int damage;
    public float fireRate;
    public float range;
    public AudioClip fireSound;
    public GameObject bulletPrefab;
}
 
// Create: Right-click Project → Game → Weapon
// Use in script:
[SerializeField] WeaponData weaponData;
 
void Shoot() {
    Debug.Log($"Firing {weaponData.weaponName} for {weaponData.damage} damage");
    AudioSource.PlayClipAtPoint(weaponData.fireSound, transform.position);
}
 
// ScriptableObject Event (Ryan Hipple pattern)
[CreateAssetMenu(menuName = "Game/GameEvent")]
public class GameEvent : ScriptableObject
{
    List<GameEventListener> listeners = new();
    public void Raise() => listeners.ForEach(l => l.OnEventRaised());
    public void Register(GameEventListener l) => listeners.Add(l);
    public void Unregister(GameEventListener l) => listeners.Remove(l);
}

public interface IDamageable {
    void TakeDamage(int amount);
}
 
public interface IInteractable {
    void Interact(GameObject interactor);
    string GetPrompt();
}
 
// Implement on any class
public class Enemy : MonoBehaviour, IDamageable {
    public void TakeDamage(int amount) { /* ... */ }
}
 
public class Barrel : MonoBehaviour, IDamageable, IInteractable {
    public void TakeDamage(int amount) { Explode(); }
    public void Interact(GameObject g) { Push(g); }
    public string GetPrompt() => "Push barrel";
}
 
// Use without knowing the concrete type
void ShootAt(GameObject target) {
    if (target.TryGetComponent<IDamageable>(out var damageable))
        damageable.TakeDamage(25);
}