Awake vs Start execution order in Unity - Quick Revision & Key Differences

Recall & Review

beginner

What is the purpose of the Awake method in Unity?

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 Unity?

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

beginner

Which method runs first: Awake or Start?

Awake runs first, immediately when the object is loaded. Start runs later, just before the first frame update and only if the script is enabled.

intermediate

Can Awake be used to reference other components on the same GameObject?

Yes, Awake is a good place to get references to other components on the same GameObject because all components are loaded by then.

intermediate

Why might you choose Start over Awake for initialization?

Start is better when you need to access other GameObjects or scripts that might not be ready during Awake. Start runs after all Awake calls are done.

Which Unity method is called first when a scene loads?

A Awake

B Start

C Update

D OnEnable

Awake is called immediately when the object is loaded, before Start.

When is the Start method called?

A Before Awake

B After Awake and before the first frame update

C Every frame

D Only if the script is disabled

Start runs after all Awake calls and before the first frame update, only if the script is enabled.

Can Awake be used to initialize variables even if the script is disabled?

A Only if Start is also called

B No

C Yes

D Only in editor mode

Awake runs regardless of whether the script is enabled or disabled.

Which method is better to use if you need to access other GameObjects that might not be ready in Awake?

A Start

B Awake

C Update

D OnDestroy

Start runs after all Awake calls, so other GameObjects are more likely to be initialized.

What happens if a script is disabled? Which method still runs?

A Only Start runs

B Neither runs

C Both Awake and Start run

D Only Awake runs

Awake runs even if the script is disabled, but Start only runs if the script is enabled.

Explain the difference between Awake and Start methods in Unity and when each is called.

Think about when the game objects are ready and script states.

Describe a situation where you would use Awake instead of Start for initialization in Unity.

Consider what is available immediately when the object loads.

Practice

1. In Unity, which method is called first when a scene loads: Awake or Start?

easy

A. Awake is called before Start.

B. Start is called before Awake.

C. Both are called at the same time.

D. Neither is called automatically.

Solution

1. Step 1: Understand Unity's initialization order

   Unity calls Awake first to initialize objects early.

2. Step 2: Recognize Start timing

   Start runs after Awake, before gameplay begins.

3. Final Answer:

   Awake is called before Start. -> Option A

4. Quick Check:

   Awake runs first = D [OK]

Hint: Remember: Awake sets up early, Start sets up later [OK]

Common Mistakes:

• Thinking Start runs before Awake
• Believing both run simultaneously
• Assuming methods need manual calls

2. Which of the following is the correct syntax to define the Awake method in a Unity C# script?

easy

A. public void awake() { }

B. private Awake() { }

C. void Awake() { }

D. Awake() => { }

Solution

1. Step 1: Recall Unity method syntax

   Unity calls Awake automatically if defined as void Awake().

2. Step 2: Check access modifiers

   Awake is usually private by default, so void Awake() is correct and common.

3. Final Answer:

   void Awake() { } -> Option C

4. Quick Check:

   Use void Awake() syntax [OK]

Hint: Awake method is usually defined as void Awake() [OK]

Common Mistakes:

• Adding public or private explicitly (not required)
• Using arrow syntax which is invalid here
• Omitting return type

3. Consider this Unity script attached to a GameObject:

void Awake() { Debug.Log("Awake called"); }
void Start() { Debug.Log("Start called"); }

What will be the order of messages in the Console when the scene starts?

medium

A. Only "Awake called" appears

B. "Start called" then "Awake called"

C. Only "Start called" appears

D. "Awake called" then "Start called"

Solution

1. Step 1: Identify method call order

   Unity calls Awake first, so "Awake called" logs first.

2. Step 2: Confirm Start runs after Awake

   Then Start runs, logging "Start called" second.

3. Final Answer:

   "Awake called" then "Start called" -> Option D

4. Quick Check:

   Awake logs first, Start logs second [OK]

Hint: Awake logs before Start logs in console [OK]

Common Mistakes:

• Assuming Start logs before Awake
• Thinking only one method logs
• Confusing method call timing

4. You wrote this script but Start never runs:

void Awake() { Debug.Log("Awake"); }
void start() { Debug.Log("Start"); }

What is the problem?

medium

A. Awake prevents Start from running.

B. start method name is lowercase, should be Start.

C. The script is missing public keyword on Start.

D. Unity does not call Start automatically.

Solution

1. Step 1: Check method names for case sensitivity

   Unity requires exact method names; Start must be capitalized.

2. Step 2: Understand Unity's method calling rules

   Lowercase start is ignored, so Start never runs.

3. Final Answer:

   start method name is lowercase, should be Start. -> Option B

4. Quick Check:

   Method names are case-sensitive [OK]

Hint: Check method names are exactly capitalized [OK]

Common Mistakes:

• Assuming Awake blocks Start
• Thinking public keyword is required
• Believing Unity calls lowercase methods

5. You have two scripts on different GameObjects:

Script A:
void Awake() { Debug.Log("A Awake"); }
void Start() { Debug.Log("A Start"); }

Script B:
void Awake() { Debug.Log("B Awake"); }
void Start() { Debug.Log("B Start"); }

What is the correct order of messages in the Console when the scene starts?

hard

A. "A Awake", "B Awake", "A Start", "B Start"

B. "A Awake", "A Start", "B Awake", "B Start"

C. "A Start", "B Start", "A Awake", "B Awake"

D. "B Awake", "A Awake", "B Start", "A Start"

Solution

1. Step 1: Understand Awake runs on all objects first

   Unity calls all Awake methods before any Start methods.

2. Step 2: Recognize Start runs after all Awake calls

   After all Awake calls, Unity calls all Start methods.

3. Final Answer:

   "A Awake", "B Awake", "A Start", "B Start" -> Option A

4. Quick Check:

   All Awake first, then all Start [OK]

Hint: All Awake run before any Start runs [OK]

Common Mistakes:

• Thinking Awake and Start alternate per object
• Assuming Start runs before Awake
• Believing order between objects is random