Lambda expression syntax in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a lambda that adds two integers.

C Sharp (C#)

Func<int, int, int> add = (x, y) => x [1] y;

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

A+

B/

C*

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using - instead of +

Using * or / which changes the operation

The lambda expression uses the + operator to add x and y.

2fill in blank

medium

Complete the code to declare a lambda that checks if a number is even.

C Sharp (C#)

Func<int, bool> isEven = 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 + or - instead of %

Using * which multiplies instead of checking remainder

The % operator gives the remainder. If remainder is 0 when divided by 2, the number is even.

3fill in blank

hard

Fix the error in the lambda that returns the square of a number.

C Sharp (C#)

Func<int, int> square = x => x [1] 2;

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A*

B**

C^

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using ** which is invalid in C#

Using ^ which is bitwise XOR, not power

In C#, the multiplication operator * is used to square a number. The ** operator is not valid.

4fill in blank

hard

Fill the blank to create a lambda that filters numbers greater than 10.

C Sharp (C#)

Func<int, bool> isGreaterThanTen = n => n [1] 10;

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A==

B<

C>

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of >

Using != which checks inequality

The lambda checks if n is greater than 10 using the > operator.

5fill in blank

hard

Fill all three blanks to create a lambda that returns a dictionary of words and their lengths for words longer than 3 characters.

C Sharp (C#)

var lengths = words.Where(w => w.Length [1] 3).ToDictionary([2] => [3].ToLower(), [2] => [2].Length);

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

A>

Bword

Cw

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > in the filter

Using inconsistent variable names in the lambdas

The lambda filters words with length greater than 3 using >. Then ToDictionary uses w as the key selector and w.Length as the value selector. The key is converted to lowercase with w.ToLower().