Awake vs Start execution order in Unity - Hands-On Comparison

Awake vs Start Execution Order in Unity

📖 Scenario: Imagine you are making a simple Unity game where you want to understand when different parts of your game objects get ready to use. Unity uses special methods called Awake and Start to prepare game objects. This project will help you see the order in which these methods run.

🎯 Goal: You will create two scripts attached to two different game objects. Each script will print messages in Awake and Start methods. You will observe the order of these messages to learn how Unity runs Awake before Start.

📋 What You'll Learn

Create two C# scripts named FirstObject and SecondObject

In each script, implement Awake and Start methods

Print messages in each method to show when they run

Attach scripts to two different game objects in the Unity scene

Run the scene and observe the console output

💡 Why This Matters

🌍 Real World

Understanding Awake and Start helps you set up game objects correctly in Unity games, avoiding bugs caused by wrong initialization order.

💼 Career

Game developers and Unity programmers must know the execution order to write reliable and efficient game code.

1

Create the FirstObject script with Awake and Start

Create a C# script called FirstObject. Inside it, write the Awake method that prints "FirstObject Awake" and the Start method that prints "FirstObject Start".

Unity

using UnityEngine;

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

Hint

Use Debug.Log inside Awake and Start methods to print messages.

2

Create the SecondObject script with Awake and Start

Create a C# script called SecondObject. Inside it, write the Awake method that prints "SecondObject Awake" and the Start method that prints "SecondObject Start".

Unity

using UnityEngine;

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

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

// Your code here

Hint

Repeat the same pattern as FirstObject but with different messages.

3

Attach scripts to two different GameObjects in the Unity scene

In the Unity Editor, create two empty GameObjects named FirstGameObject and SecondGameObject. Attach the FirstObject script to FirstGameObject and the SecondObject script to SecondGameObject.

Unity

// In Unity Editor, create two GameObjects and attach scripts
// Your code here (this step is done in Unity Editor, no code needed)

Hint

This step is done in the Unity Editor by dragging scripts onto GameObjects.

4

Run the scene and observe the console output

Run the Unity scene and observe the console. You should see the messages printed in this order: FirstObject Awake, SecondObject Awake, FirstObject Start, SecondObject Start. Write a Debug.Log statement that prints "Check console for Awake and Start order".

Unity

Debug.Log("Check console for Awake and Start order");

Hint

Look at the Unity Console window to see the order of messages.

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