⚙️ How Unity "Talks" to Your Code

• You’ve learned how to write scripts.
• Now let’s learn how Unity knows when and how to run your code.

In Unity, there are special built-in methods - like Start(), Update(), and OnCollisionEnter() - that Unity calls automatically at specific times.

This is made possible through MonoBehaviour, Unity’s magical base class that connects your scripts to the engine.

👑 What is MonoBehaviour?

All your Unity scripts inherit from this class:

1public class MyScript : MonoBehaviour2{3    // Magic lives here4}

By inheriting from MonoBehaviour, Unity can call special methods like Start() and Update() without you needing to do anything else.

🚀 Start() – Runs Once

1void Start()2{3    Debug.Log("The game has started!");4}

• Called once at the very beginning (when the object becomes active)
• Great for initialization, setting values, or printing welcome messages
• Happens before the first Update()

🔁 Update() – Runs Every Frame

1void Update()2{3    Debug.Log("Still running...");4}

• Called every frame - 60+ times per second depending on your hardware
• Ideal for real-time logic like: Player input
• Moving objects
• Checking timers

🧪 Example Script

1using UnityEngine;2 3public class HelloUnity : MonoBehaviour4{5    void Start()6    {7        Debug.Log("Game started");8    }9 10    void Update()11    {12        Debug.Log("Frame running...");13    }14}

• Attach this script to a GameObject, hit play, and check the Console:
• You’ll see “Game started” once, and “Frame running…” repeatedly.

🛠️ Other Useful MonoBehaviour Methods

We’ll explore these more in future lessons. For now, Start() and Update() are your go-to tools.

🧠 Recap

• MonoBehaviour connects your code to Unity’s event system
• Start() runs once when the object activates
• Update() runs every frame (use it for live logic)
• These methods let your scripts become interactive parts of the game world

🧪 Mini Challenge: Frame Counter

1. Create a new script called FrameTracker.cs
2. In Update(), increase a counter every frame
3. Every 60 frames, print "One second-ish passed"
4. Reset the counter after logging

Bonus: Try printing a message every 5 seconds using a float timer instead!

🚀 What’s Next?

• Congrats, you’ve finished Section 2! 🎉
• You now know the basics of variables, methods, logic, loops, and Unity’s script lifecycle.

Next up, we’ll build our very first game together - a classic clicker game to put your skills into action!

👆 Go to Section 3 → Your First Game – Clicker Game