LINQ method syntax in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select all even numbers from the list using LINQ method syntax.

C Sharp (C#)

var evens = numbers.Where(n => n [1] 2 == 0).ToList();

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

A%

B/

C*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using division operator '/' instead of modulo '%'.

Using multiplication '*' or addition '+' operators incorrectly.

The modulo operator % returns the remainder. To find even numbers, we check if n % 2 == 0.

2fill in blank

medium

Complete the code to order the list of names alphabetically using LINQ method syntax.

C Sharp (C#)

var sortedNames = names.[1](name => name);

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AGroupBy

BWhere

CSelect

DOrderBy

Attempts:

3 left

💡 Hint

Common Mistakes

Using Where which filters instead of sorting.

Using Select which projects elements.

Using GroupBy which groups elements.

The OrderBy method sorts elements in ascending order based on a key.

3fill in blank

hard

Fix the error in the code to find the first number greater than 10 using LINQ method syntax.

C Sharp (C#)

var first = numbers.[1](n => n > 10);

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AFirstOrDefault

BOrderBy

CSelect

DWhere

Attempts:

3 left

💡 Hint

Common Mistakes

Using Where which returns a collection, not a single element.

Using Select which projects elements.

Using OrderBy which sorts elements.

FirstOrDefault returns the first element matching the condition or default if none found. Where returns a collection, not a single element.

4fill in blank

hard

Fill both blanks to create a dictionary from a list of words where the key is the word and the value is its length.

C Sharp (C#)

var wordLengths = words.ToDictionary([1] => [1], [2] => [2].Length);

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Aword

Bw

Citem

Dx

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently.

Using variable names not matching in both selectors.

We use the same variable name word for both key and value selector functions.

5fill in blank

hard

Fill all three blanks to filter numbers greater than 5, order them descending by their squares.

C Sharp (C#)

var result = numbers.Where([1] => [1] [2] 5).OrderByDescending([3] => [3] * [3]).ToList();

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

An

B>

Cx

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' for filtering.

Mixing variable names between lambdas.

Not squaring the number in the ordering.

We filter numbers greater than 5 using n > 5, then order descending by their squares using x => x * x.