Task.WhenAny for first completion in C Sharp (C#) - Mini Project: Build & Apply

Task.WhenAny for first completion

📖 Scenario: You are building a simple program that runs multiple tasks and wants to know which one finishes first.

🎯 Goal: Create three tasks that complete after different delays, then use Task.WhenAny to find and display the first task that finishes.

📋 What You'll Learn

Create three tasks with different delays

Use a variable to hold the first completed task

Use Task.WhenAny to get the first completed task

Print which task finished first

💡 Why This Matters

🌍 Real World

In real apps, you might start multiple operations and want to react as soon as one finishes, like loading data from multiple sources and using the fastest response.

💼 Career

Understanding Task.WhenAny is important for asynchronous programming in C#, which is common in web, desktop, and mobile app development.

1

Create three tasks with different delays

Create three tasks called task1, task2, and task3 that each delay for 3000, 2000, and 1000 milliseconds respectively using Task.Delay.

C Sharp (C#)

# Create three tasks with different delays
// Your code here

Need a hint?

Use Task.Delay(milliseconds) to create tasks that complete after a delay.

2

Create an array of tasks

Create an array called tasks that contains task1, task2, and task3.

C Sharp (C#)

using System.Threading.Tasks;

Task task1 = Task.Delay(3000);
Task task2 = Task.Delay(2000);
Task task3 = Task.Delay(1000);

// Create an array called tasks with task1, task2, and task3
// Your code here

Need a hint?

Use new Task[] { } to create an array of tasks.

3

Use Task.WhenAny to get the first completed task

Create a variable called firstFinished and assign it the result of await Task.WhenAny(tasks) inside an async method.

C Sharp (C#)

using System.Threading.Tasks;
using System;

class Program
{
    static async Task Main()
    {
        Task task1 = Task.Delay(3000);
        Task task2 = Task.Delay(2000);
        Task task3 = Task.Delay(1000);

        Task[] tasks = new Task[] { task1, task2, task3 };

        // Use Task.WhenAny to get the first finished task
        // Your code here
    }
}

Need a hint?

Remember to make the Main method async to use await.

4

Print which task finished first

Print "Task 1 finished first" if firstFinished is task1, "Task 2 finished first" if it is task2, or "Task 3 finished first" if it is task3.

C Sharp (C#)

using System.Threading.Tasks;
using System;

class Program
{
    static async Task Main()
    {
        Task task1 = Task.Delay(3000);
        Task task2 = Task.Delay(2000);
        Task task3 = Task.Delay(1000);

        Task[] tasks = new Task[] { task1, task2, task3 };

        Task firstFinished = await Task.WhenAny(tasks);

        // Print which task finished first
        // Your code here
    }
}

Need a hint?

Compare firstFinished with each task variable and print the matching message.