Deferred execution behavior in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a list of even numbers using deferred execution.

C Sharp (C#)

var numbers = new List<int> {1, 2, 3, 4, 5};
var evens = numbers.Where(n => n [1] 2 == 0);

Drag options to blanks, or click blank then click option'

A*

B/

C%

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using division / instead of modulo % to check even numbers.

The modulo operator % returns the remainder. Using n % 2 == 0 checks if a number is even.

2fill in blank

medium

Complete the code to demonstrate deferred execution by modifying the source list after query creation.

C Sharp (C#)

var numbers = new List<int> {1, 2, 3};
var query = numbers.Where(n => n > [1]);
numbers.Add(4);
foreach(var num in query) Console.WriteLine(num);

Drag options to blanks, or click blank then click option'

A1

B3

C2

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a number that excludes the newly added element from the query.

Using n > 1 will include numbers greater than 1, so after adding 4, it will be included in the output, showing deferred execution.

3fill in blank

hard

Fix the error in the code to correctly demonstrate deferred execution with LINQ.

C Sharp (C#)

var list = new List<int> {1, 2, 3};
var result = list.Select(x => x * 2).ToList();
list.Add(4);
var query = list.Select(x => x [1] 2);
foreach(var item in query) Console.WriteLine(item);

Drag options to blanks, or click blank then click option'

A*

B+

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition or division instead of multiplication.

The * operator multiplies each element by 2. Using ToList() earlier forces immediate execution, but the second query uses deferred execution.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that filters and transforms elements with deferred execution.

C Sharp (C#)

var words = new List<string> {"apple", "bee", "cat", "dog"};
var dict = words.Where(w => w.Length [1] 3)
                .ToDictionary(w => w, w => w.[2]());

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A>

BToUpper

C<

DToLower

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong comparison operator or string method.

The code filters words with length greater than 3 and converts them to uppercase in the dictionary values.

5fill in blank

hard

Fill all three blanks to create a LINQ query that filters, transforms, and orders numbers demonstrating deferred execution.

C Sharp (C#)

var nums = new List<int> {5, 3, 8, 1, 4};
var query = nums.Where(n => n [1] 3)
                .Select(n => n [2] 1)
                .OrderBy(n => n [3] 2);
foreach(var n in query) Console.WriteLine(n);

Drag options to blanks, or click blank then click option'

A>

B+

C*

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong operators causing incorrect filtering or ordering.

The query filters numbers greater than 3, adds 1 to each, then orders them by their value multiplied by 2.