Deferred execution behavior in C Sharp (C#) - Mini Project: Build & Apply

Understanding Deferred Execution in C#

📖 Scenario: Imagine you have a list of numbers and you want to find all numbers greater than a certain value. In C#, queries using LINQ are not run immediately but only when you actually use the results. This is called deferred execution.

🎯 Goal: You will create a list of numbers, set a threshold value, write a LINQ query to select numbers greater than the threshold, and then print the results to see deferred execution in action.

📋 What You'll Learn

Create a list of integers called numbers with the values 1, 3, 5, 7, 9

Create an integer variable called threshold and set it to 4

Write a LINQ query called filteredNumbers that selects numbers greater than threshold

Print each number in filteredNumbers using a foreach loop

💡 Why This Matters

🌍 Real World

Filtering data based on conditions is common in apps like shopping sites, where you show products above a certain price.

💼 Career

Understanding deferred execution helps you write efficient C# code that only processes data when needed, saving time and resources.

1

Create the list of numbers

Create a list of integers called numbers with these exact values: 1, 3, 5, 7, 9.

C Sharp (C#)

# Create the list of numbers
// Your code here

Need a hint?

Use List<int> and initialize it with the values inside curly braces.

2

Set the threshold value

Create an integer variable called threshold and set it to 4.

C Sharp (C#)

using System.Collections.Generic;

List numbers = new List { 1, 3, 5, 7, 9 };

// Create the threshold variable
// Your code here

Need a hint?

Use int threshold = 4; to create the variable.

3

Write the LINQ query with deferred execution

Write a LINQ query called filteredNumbers that selects numbers from numbers greater than threshold. Use var filteredNumbers = numbers.Where(n => n > threshold);.

C Sharp (C#)

using System.Collections.Generic;
using System.Linq;

List numbers = new List { 1, 3, 5, 7, 9 };

int threshold = 4;

// Write the LINQ query to select numbers greater than threshold
// Your code here

Need a hint?

Use numbers.Where(n => n > threshold) to create the query.

4

Print the filtered numbers

Use a foreach loop to print each number in filteredNumbers on its own line.

C Sharp (C#)

using System.Collections.Generic;
using System.Linq;

List numbers = new List { 1, 3, 5, 7, 9 };

int threshold = 4;

var filteredNumbers = numbers.Where(n => n > threshold);

// Print each number in filteredNumbers
// Your code here

Need a hint?

Use foreach (int number in filteredNumbers) and Console.WriteLine(number); inside the loop.