Truthy and falsy values (only nil and false are falsy) in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the variable is truthy.

Ruby

if [1]
  puts "It's truthy!"
else
  puts "It's falsy!"
end

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

Atrue

Bnil

Cfalse

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 0 as falsy because in some languages 0 is falsy.

Choosing nil or false as truthy.

In Ruby, only false and nil are falsy. Everything else, including true, is truthy.

2fill in blank

medium

Complete the code to print 'Falsy' only if the value is falsy.

Ruby

value = [1]
if !value
  puts 'Falsy'
else
  puts 'Truthy'
end

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

Afalse

B42

C"string"

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using true or other values that are truthy.

Confusing string or number as falsy.

Only false and nil are falsy in Ruby. Here, false makes the condition true after negation.

3fill in blank

hard

Fix the error in the code to correctly check for falsy values.

Ruby

if [1] == false || [1] == nil
  puts 'Falsy value'
else
  puts 'Truthy value'
end

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

Aval

Bvalue

Cfalse

Dnil

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names causing errors.

Using literal false or nil instead of variable.

The variable to check must be consistent. Using value matches the variable being tested.

4fill in blank

hard

Fill both blanks to create a hash of words and their lengths, but only include words longer than 3 characters.

Ruby

words = ["cat", "house", "dog", "elephant"]
lengths = words.select { |word| [1] [2] 3 }.map { |word| [word, [1]] }.to_h

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

Aword.length

Bword.size

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > causing wrong filtering.

Using word instead of length method.

Use word.length to get the length and > to filter words longer than 3 characters.

5fill in blank

hard

Fill all three blanks to create a hash of uppercase words and their lengths, including only words longer than 4 characters.

Ruby

words = ["apple", "bat", "carrot", "dog"]
result = words.select { |w| [2] [3] 4 }.map { |w| [[1], [2]] }.to_h

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

Aw.upcase

Bw.length

C>

Dw

Attempts:

3 left

💡 Hint

Common Mistakes

Using the word itself as key instead of uppercase.

Using less than operator causing wrong filtering.

Use w.upcase as the key, w.length as the value, and filter words with length greater than 4.