DontDestroyOnLoad usage in Unity - Mini Project: Build & Apply

Using DontDestroyOnLoad in Unity

📖 Scenario: You are making a simple Unity game where you want a music player object to keep playing music even when you change scenes. Normally, when you load a new scene, all objects are destroyed and recreated. But you want the music to continue without restarting.

🎯 Goal: Build a Unity script that uses DontDestroyOnLoad to keep a GameObject alive across scene changes.

📋 What You'll Learn

Create a C# script called MusicPlayer

In MusicPlayer, use DontDestroyOnLoad(gameObject) to keep the object alive

Add a check to prevent duplicates if the object already exists

Print a message to the console when the object is kept alive

💡 Why This Matters

🌍 Real World

Games often need objects like music players or managers to persist across scenes without restarting or duplicating.

💼 Career

Understanding how to manage persistent objects is important for game developers working with Unity to create smooth player experiences.

1

Create the MusicPlayer script with Awake method

Create a C# script called MusicPlayer with an Awake() method that prints "MusicPlayer Awake" to the console.

Unity

using UnityEngine;

public class MusicPlayer : MonoBehaviour
{
    // Your code here
}

Need a hint?

The Awake() method runs when the object is created. Use Debug.Log to print messages.

2

Add DontDestroyOnLoad to keep the object alive

Inside the Awake() method, add DontDestroyOnLoad(gameObject); to keep the GameObject alive when loading new scenes.

Unity

using UnityEngine;

public class MusicPlayer : MonoBehaviour
{
    void Awake()
    {
        Debug.Log("MusicPlayer Awake");
        // Your code here
    }
}

Need a hint?

Use DontDestroyOnLoad(gameObject); inside Awake() to keep the object alive across scenes.

3

Prevent duplicate MusicPlayer objects

Modify the Awake() method to check if another MusicPlayer already exists. If yes, destroy this duplicate object using Destroy(gameObject);. Use FindObjectsOfType<MusicPlayer>() to find existing objects.

Unity

using UnityEngine;

public class MusicPlayer : MonoBehaviour
{
    void Awake()
    {
        Debug.Log("MusicPlayer Awake");
        // Your code here
    }
}

Need a hint?

Use FindObjectsOfType<MusicPlayer>() to find all MusicPlayer objects. If more than one exists, destroy the new one.

4

Print confirmation when object is kept alive

Add a Debug.Log message inside Awake() after DontDestroyOnLoad(gameObject); that prints "MusicPlayer will not be destroyed on load".

Unity

using UnityEngine;

public class MusicPlayer : MonoBehaviour
{
    void Awake()
    {
        MusicPlayer[] players = FindObjectsOfType();
        if (players.Length > 1)
        {
            Destroy(gameObject);
            return;
        }
        Debug.Log("MusicPlayer Awake");
        DontDestroyOnLoad(gameObject);
        // Your code here
    }
}

Need a hint?

Print a message after calling DontDestroyOnLoad to confirm the object stays alive.