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

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select all numbers from the list.

C Sharp (C#)

var numbers = new List<int> {1, 2, 3, 4, 5};
var query = from num in numbers select [1];

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

Anum

Bnumbers

Cnumber

Dn

Attempts:

3 left

💡 Hint

Common Mistakes

Using the collection name instead of the iteration variable.

Using a variable name not defined in the query.

In LINQ query syntax, you select the variable defined in the from clause, here 'num'.

2fill in blank

medium

Complete the code to filter numbers greater than 3.

C Sharp (C#)

var numbers = new List<int> {1, 2, 3, 4, 5};
var query = from num in numbers where num [1] 3 select num;

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

A<=

B==

C<

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>'.

Using '==' which only selects numbers equal to 3.

To filter numbers greater than 3, use the '>' operator in the where clause.

3fill in blank

hard

Fix the error in the LINQ query to order numbers ascending.

C Sharp (C#)

var numbers = new List<int> {5, 3, 1, 4, 2};
var query = from num in numbers orderby num [1] select num;

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

Adescending

Basc

Cascending

Dascend

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'descending', which orders from highest to lowest.

Using invalid shorthands like 'asc' or 'ascend'.

In C# LINQ query syntax, use 'ascending' after 'orderby' to explicitly order ascending (this is the default behavior).

4fill in blank

hard

Fill both blanks to select names starting with 'A' and order them descending.

C Sharp (C#)

var names = new List<string> {"Alice", "Bob", "Anna", "Mike"};
var query = from name in names where name.StartsWith([1]) orderby name [2] select name;

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

A"A"

B"a"

Cascending

Ddescending

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'a' which misses uppercase names.

Using 'ascending' instead of 'descending' for order.

To select names starting with uppercase 'A', use "A" and order descending with 'descending'.

5fill in blank

hard

Fill all three blanks to select even numbers, order ascending, and select their squares.

C Sharp (C#)

var numbers = new List<int> {1, 2, 3, 4, 5};
var query = from num in numbers where num [1] 2 == 0 orderby num [2] select num * [3];

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

A%

Bascending

Cnum

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong operator like '+' or '-' for even check.

Using 'descending' instead of 'ascending'.

Using incorrect value like '2' instead of 'num' for squaring.

Use '%' to check even numbers (num % 2 == 0), 'ascending' to order ascending, and 'num' to select squares (num * num).