Why blocks are fundamental to Ruby - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print each number using a block.

Ruby

numbers = [1, 2, 3]
numbers.each [1] |num| puts num end

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

Ado

Bif

Cwhile

Dfor

Attempts:

3 left

💡 Hint

Common Mistakes

Using keywords like if or while instead of do to start a block.

Omitting the block entirely.

The do keyword starts a block in Ruby, which is used here with each to print each number.

2fill in blank

medium

Complete the code to yield control to the block with a value.

Ruby

def greet
  yield [1]
end

greet { |name| puts "Hello, #{name}!" }

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

Aself

B"Ruby"

Cblock

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a variable name that is not defined.

Not passing any value to yield.

The yield keyword passes control to the block, sending the value "Ruby" as an argument.

3fill in blank

hard

Fix the error in the block syntax to correctly sum numbers.

Ruby

sum = 0
[1, 2, 3].each [1] |n| sum += n end
puts sum

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

Ado

Bif

Cwhile

Dfor

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect keywords like if or while to start a block.

Missing the block entirely.

The do keyword correctly starts the block for the each method to sum the numbers.

4fill in blank

hard

Complete the code to create a hash with word lengths for words longer than 3 letters.

Ruby

words = ["cat", "house", "tree", "a"]
lengths = { word=> [1] for word in words if len(word) > 3 }

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A:

Blen(word)

Clength

D=>

Attempts:

3 left

💡 Hint

Common Mistakes

Using colon (:) instead of => for hash key-value pairs.

Using incorrect method names for length.

In Ruby, the hash key-value pair uses =>. The length of the word is obtained by len(word) (though in Ruby it should be word.length, this exercise uses len for simplicity).

5fill in blank

hard

Fill all three blanks to create a hash of uppercase words and their lengths for words longer than 2 letters.

Ruby

words = ["dog", "cat", "a", "bird"]
result = { [1]: [2] for w in words if w.length [3] 2 }

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

Aw.upcase

Bw.length

C>

Dw.downcase

Attempts:

3 left

💡 Hint

Common Mistakes

Using downcase instead of upcase for keys.

Using incorrect comparison operators.

The hash uses the uppercase word as key (w.upcase), the length as value (w.length), and filters words longer than 2 letters (>).