Coroutine basics (IEnumerator) in Unity - Mini Project: Build & Apply

Coroutine basics (IEnumerator)

📖 Scenario: You are making a simple Unity game where you want to show a message, wait for a few seconds, and then show another message.

🎯 Goal: Build a coroutine using IEnumerator that waits for 3 seconds before printing a message in the Unity console.

📋 What You'll Learn

Create a coroutine method using IEnumerator

Use yield return new WaitForSeconds(3) to wait

Start the coroutine from the Start() method

Print messages before and after the wait

💡 Why This Matters

🌍 Real World

Coroutines let you pause and resume actions in games, like waiting for animations or delays without freezing the whole game.

💼 Career

Understanding coroutines is important for game developers to manage timed events and smooth gameplay experiences.

1

Create a Start() method and print the first message

Create a Start() method inside a MonoBehaviour class called MessagePrinter. Inside Start(), write Debug.Log("Starting coroutine...") to print the first message.

Unity

using UnityEngine;

public class MessagePrinter : MonoBehaviour
{
    // Create Start() method and print the first message
    // Your code here
}

Need a hint?

Remember, Start() is a special method called automatically when the game starts.

2

Create a coroutine method called WaitAndPrint()

Add a coroutine method called WaitAndPrint() that returns IEnumerator. Inside it, write yield return new WaitForSeconds(3); to wait for 3 seconds.

Unity

using UnityEngine;

public class MessagePrinter : MonoBehaviour
{
    void Start()
    {
        Debug.Log("Starting coroutine...");
    }

    // Create IEnumerator method WaitAndPrint() with 3 seconds wait
    // Your code here
}

Need a hint?

Use IEnumerator as the return type and yield return new WaitForSeconds(3); to pause.

3

Start the coroutine WaitAndPrint() inside Start()

Inside the Start() method, add the line StartCoroutine(WaitAndPrint()); to start the coroutine.

Unity

using UnityEngine;
using System.Collections;

public class MessagePrinter : MonoBehaviour
{
    void Start()
    {
        Debug.Log("Starting coroutine...");
        // Start the coroutine WaitAndPrint()
        // Your code here
    }

    IEnumerator WaitAndPrint()
    {
        yield return new WaitForSeconds(3);
    }
}

Need a hint?

Use StartCoroutine() to run the coroutine method.

4

Print a message after the wait inside WaitAndPrint()

Inside the WaitAndPrint() coroutine, after the yield return line, add Debug.Log("3 seconds passed!"); to print the message after waiting.

Unity

using UnityEngine;
using System.Collections;

public class MessagePrinter : MonoBehaviour
{
    void Start()
    {
        Debug.Log("Starting coroutine...");
        StartCoroutine(WaitAndPrint());
    }

    IEnumerator WaitAndPrint()
    {
        yield return new WaitForSeconds(3);
        // Print message after wait
        // Your code here
    }
}

Need a hint?

Use Debug.Log() to print the message after the wait.