Lambda creation and behavior in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a lambda that adds 5 to its input.

Ruby

add_five = ->(x) { x [1] 5 }

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

A/

B-

C*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using - instead of + will subtract instead of add.

Using * or / will multiply or divide, which is not the goal.

The lambda adds 5 to the input using the + operator.

2fill in blank

medium

Complete the code to call the lambda with argument 10.

Ruby

result = add_five.[1](10)

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

Aexecute

Bcall

Crun

Dapply

Attempts:

3 left

💡 Hint

Common Mistakes

Using run, execute, or apply will cause errors because these methods don't exist for lambdas.

In Ruby, lambdas are called using the call method.

3fill in blank

hard

Fix the error in the lambda creation syntax.

Ruby

my_lambda = lambda [1] |x| x * 2 }

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

A[

B(

C{

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses or square brackets instead of curly braces causes syntax errors.

The correct syntax for lambda creation uses curly braces {} around the block.

4fill in blank

hard

Fill both blanks to create a lambda that checks if a number is even.

Ruby

is_even = ->(n) { n [1] 2 [2] 0 }

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

A%

B==

C!=

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using != instead of == will check for odd numbers.

Using + instead of % will add numbers, not check evenness.

The lambda uses the modulo operator % to get the remainder and checks if it equals 0 with ==.

5fill in blank

hard

Fill both blanks to create a lambda that returns the uppercase version of a string if its length is greater than 3.

Ruby

transform = ->(s) { s.length [1] 3 ? s.[2] : s }

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

A<

Bupcase

C>

Ddowncase

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > will invert the condition.

Using downcase instead of upcase changes the string to lowercase.

The lambda checks if the string length is greater than 3 using >. If true, it returns the uppercase string with upcase, otherwise returns the original string.