MonoBehaviour lifecycle in Unity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Awake() method in a MonoBehaviour?

Awake() is called when the script instance is being loaded. It is used to initialize variables or states before the game starts. It runs even if the script component is disabled.

beginner

When is the Start() method called in the MonoBehaviour lifecycle?

Start() is called before the first frame update, but only if the script component is enabled. It is used to set up things that depend on other objects being initialized.

intermediate

What is the difference between Update() and FixedUpdate()?

Update() runs once per frame and is used for regular frame-based logic like input checking. FixedUpdate() runs at fixed time intervals and is used for physics calculations.

intermediate

What does the OnEnable() method do in the MonoBehaviour lifecycle?

OnEnable() is called every time the script component is enabled or the GameObject it is attached to becomes active. It is useful for subscribing to events or resetting states.

intermediate

Explain the role of OnDestroy() in MonoBehaviour.

OnDestroy() is called when the MonoBehaviour will be destroyed. It is used to clean up resources, unsubscribe from events, or save data before the object is removed.

Which MonoBehaviour method is called only once when the script instance is loaded?

A Update()

B Start()

C FixedUpdate()

D Awake()

Awake() is called once when the script instance is loaded, before any other method.

Which method is best for handling physics updates in Unity?

A FixedUpdate()

B Update()

C LateUpdate()

D OnEnable()

FixedUpdate() runs at fixed intervals and is designed for physics calculations.

When is Start() called in the MonoBehaviour lifecycle?

A Before the script instance is loaded

B Before the first frame update if the script is enabled

C Every frame

D When the object is destroyed

Start() runs once before the first frame update, but only if the script is enabled.

What happens when OnEnable() is called?

A The script component or GameObject becomes active

B The frame updates

C The object is destroyed

D The script instance is loaded

OnEnable() is called when the script or GameObject becomes active.

Which method should you use to clean up resources before an object is removed?

A Awake()

B Start()

C OnDestroy()

D Update()

OnDestroy() is called before the object is destroyed and is used for cleanup.

Describe the order of MonoBehaviour lifecycle methods from object creation to destruction.

Think about what happens when the object is created, enabled, updated, disabled, and destroyed.

Explain when and why you would use FixedUpdate() instead of Update().

Consider timing and physics calculations.