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.