Awake vs Start execution order in Unity - Practice Questions

Challenge - 5 Problems

❓ Predict Output

intermediate

Order of Awake and Start in Unity

What is the output order when the following Unity script runs?

Unity

using UnityEngine;

public class TestOrder : MonoBehaviour
{
    void Awake()
    {
        Debug.Log("Awake called");
    }

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

A Awake called\nStart called

B Start called\nAwake called

C Start called

D Awake called

💡 Hint

Awake is called before Start in Unity's lifecycle.

In Unity, Awake is called first when the script instance is loaded, then Start is called before the first frame update.

🧠 Conceptual

intermediate

Purpose of Awake vs Start

Which statement best describes the difference between Awake and Start methods in Unity?

A Start is used for physics updates, Awake is for rendering.

B Awake is used for initialization before any Start methods are called, Start is used for setup after all Awake calls.

C Awake is called every frame, Start is called once.

D Start is called before Awake and is used for initialization.

💡 Hint

Think about when each method is called during the script lifecycle.

Awake is called when the script instance is loaded, before any Start methods. Start is called before the first frame update, after all Awake calls.

❓ Predict Output

advanced

Execution order with multiple scripts

Given two scripts attached to different GameObjects, what is the order of output?

Unity

using UnityEngine;

public class ScriptA : MonoBehaviour
{
    void Awake() { Debug.Log("ScriptA Awake"); }
    void Start() { Debug.Log("ScriptA Start"); }
}

public class ScriptB : MonoBehaviour
{
    void Awake() { Debug.Log("ScriptB Awake"); }
    void Start() { Debug.Log("ScriptB Start"); }
}

A ScriptA Awake\nScriptB Awake\nScriptA Start\nScriptB Start

B ScriptA Awake\nScriptA Start\nScriptB Awake\nScriptB Start

C ScriptB Start\nScriptB Awake\nScriptA Start\nScriptA Awake

D ScriptB Awake\nScriptA Awake\nScriptB Start\nScriptA Start

💡 Hint

Awake is called on all scripts before any Start is called.

Unity calls Awake on all scripts first, then calls Start on all scripts. The order of Awake calls depends on script execution order or scene hierarchy but Awake always precedes Start.

🔧 Debug

advanced

Why Start is not called?

Why does the Start method not get called in this script attached to a disabled GameObject?

Unity

using UnityEngine;

public class DisabledStart : MonoBehaviour
{
    void Awake() { Debug.Log("Awake called"); }
    void Start() { Debug.Log("Start called"); }
}

A Awake disables Start automatically.

B Start is called before Awake, so it was missed.

C Start requires a public modifier to be called.

D Start is only called if the GameObject is active when the scene starts; disabled objects do not call Start until enabled.

💡 Hint

Think about when Unity calls Start relative to GameObject activation.

Start is called only if the GameObject is active when the scene starts. If the GameObject is disabled, Start is delayed until it is enabled.

🧠 Conceptual

expert

Awake and Start with Script Execution Order

If Script Execution Order is set so ScriptB runs before ScriptA, which statement is true about Awake and Start calls?

A Both Awake and Start calls strictly follow Script Execution Order.

B Start calls follow Script Execution Order, but Awake calls happen after all Start calls.

C Awake calls follow Script Execution Order, but Start calls happen after all Awake calls regardless of order.

D Script Execution Order does not affect Awake or Start calls.

💡 Hint

Consider Unity's lifecycle and how Script Execution Order affects Awake and Start.

Unity calls Awake methods in Script Execution Order, but Start methods are called only after all Awake calls complete, regardless of order.

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