Scene loading and unloading in Unity - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this scene loading code?

Consider the following Unity C# code snippet that loads a scene asynchronously. What will be printed in the console when the scene finishes loading?

Unity

using UnityEngine;
using UnityEngine.SceneManagement;

public class SceneLoader : MonoBehaviour
{
    void Start()
    {
        StartCoroutine(LoadYourAsyncScene());
    }

    System.Collections.IEnumerator LoadYourAsyncScene()
    {
        AsyncOperation asyncLoad = SceneManager.LoadSceneAsync("Level2");

        while (!asyncLoad.isDone)
        {
            yield return null;
        }

        Debug.Log("Scene Loaded");
    }
}

A Scene Loaded

B No output

C Error: Scene not found

D Scene Loading

💡 Hint

Look at when Debug.Log is called in relation to the async loading completion.

The Debug.Log("Scene Loaded") is called after the asyncLoad.isDone becomes true, meaning the scene finished loading.

🧠 Conceptual

intermediate

Which method unloads a scene in Unity?

You want to remove a scene from memory in Unity during runtime. Which method should you use?

A SceneManager.UnloadSceneAsync("SceneName")

B SceneManager.LoadScene("SceneName")

C SceneManager.ReloadScene("SceneName")

D SceneManager.AddScene("SceneName")

💡 Hint

Think about the method that removes a scene asynchronously.

SceneManager.UnloadSceneAsync unloads the specified scene asynchronously, freeing memory.

🔧 Debug

advanced

Why does this scene not unload properly?

This code tries to unload a scene but the scene remains loaded. What is the likely cause?

Unity

using UnityEngine.SceneManagement;

void UnloadScene()
{
    SceneManager.UnloadSceneAsync("GameScene");
}

A The scene name is case sensitive and "GameScene" is incorrect

B UnloadSceneAsync requires a callback to complete unloading

C UnloadSceneAsync only works in editor mode

D The scene is set as the active scene and cannot be unloaded

💡 Hint

Check if the active scene can be unloaded.

Unity does not allow unloading the active scene. You must set another scene active before unloading.

📝 Syntax

advanced

Which code correctly loads a scene additively?

You want to load a scene without unloading the current one. Which code snippet is correct?

A SceneManager.LoadSceneAsync("Level3", LoadSceneMode.Single);

B SceneManager.LoadScene("Level3", LoadSceneMode.Additive);

C SceneManager.LoadSceneAdditive("Level3");

D SceneManager.LoadScene("Level3", LoadMode.Additive);

💡 Hint

Check the correct enum name for additive loading.

LoadSceneMode.Additive is the correct enum to load a scene additively.

🚀 Application

expert

How to ensure a scene is fully unloaded before loading another?

You want to unload "SceneA" and then load "SceneB" only after unloading completes. Which approach ensures this order?

Unity

using UnityEngine;
using UnityEngine.SceneManagement;

public class SceneSwitcher : MonoBehaviour
{
    public void SwitchScenes()
    {
        // Fill in the blanks
    }
}

A

SceneManager.LoadScene("SceneB");
SceneManager.UnloadSceneAsync("SceneA");

B

SceneManager.UnloadSceneAsync("SceneA");
SceneManager.LoadScene("SceneB");

C

StartCoroutine(UnloadThenLoad());

IEnumerator UnloadThenLoad()
{
    yield return SceneManager.UnloadSceneAsync("SceneA");
    SceneManager.LoadScene("SceneB");
}

D

SceneManager.UnloadScene("SceneA");
SceneManager.LoadSceneAsync("SceneB");

💡 Hint

Think about waiting for the unload operation to finish before loading.

Yielding the AsyncOperation returned by UnloadSceneAsync waits until unloading finishes before loading the next scene.