Why LINQ is needed in C Sharp (C#) - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a list of integers.

C Sharp (C#)

List<int> numbers = new List<int> [1];

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A[]

B()

C{}

D<>

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets instead of parentheses.

Using curly braces without initialization.

The correct syntax to create a new list in C# uses parentheses () after the constructor.

2fill in blank

medium

Complete the code to filter numbers greater than 5 using LINQ.

C Sharp (C#)

var filtered = numbers.Where(n => n [1] 5);

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A<

B==

C>

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using less than operator instead of greater than.

Using equality operator which filters only numbers equal to 5.

The Where method filters elements. To get numbers greater than 5, use the greater than operator >.

3fill in blank

hard

Fix the error in the LINQ query to select names starting with 'A'.

C Sharp (C#)

var result = names.Where(name => name.[1]("A"));

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AStartsWith

BstartWith

CstartsWith

DStartwith

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect casing for method name.

Misspelling the method name.

The correct method name is StartsWith with capital S and W.

4fill in blank

hard

Fill both blanks to create a dictionary from a list using LINQ.

C Sharp (C#)

var dict = people.ToDictionary([1] => [2].Id);

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Aperson

Bp

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in the lambda expression.

Using variable names not declared in the lambda.

In the lambda expression, the variable name must be consistent. Here, p is used both times.

5fill in blank

hard

Fill all three blanks to select and order names using LINQ.

C Sharp (C#)

var orderedNames = people.Select([1] => [2].Name).OrderBy([3] => [3]);

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Aperson

Bp

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in the two lambda expressions.

Using variable names that are not declared.

Use p as the variable in Select and OrderBy for clarity and consistency.