Everything is an object mental model in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the class of the number 10.

Ruby

puts 10.[1]

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Aclass

Btype

Ckind

Dobject

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'type' instead of 'class' causes an error.

In Ruby, class is the method to get the class of an object.

2fill in blank

medium

Complete the code to call the upcase method on the string 'hello'.

Ruby

puts 'hello'.[1]

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Adowncase

Bupcase

Ccapitalize

Dreverse

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'capitalize' only changes the first letter.

The upcase method converts all letters in a string to uppercase.

3fill in blank

hard

Fix the error in the code to check if 5 is an object.

Ruby

puts 5.[1](Object)

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Aobject?

Bis_object?

Cis_a?

Dinstance_of?

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'object?' or 'is_object?' are not valid Ruby methods.

The is_a? method checks if an object is an instance of a class or its subclass.

4fill in blank

hard

Fill both blanks to create a hash where keys are strings and values are their lengths.

Ruby

lengths = ['cat', 'dog', 'bird'].each_with_object({}) { |word, h| h[[1]] = [2] }

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Aword

Bword.length

Cword.size

Dword.count

Attempts:

3 left

💡 Hint

Common Mistakes

Using word.size also works but is not the expected answer here.

The key is the word itself, and the value is its length using length.

5fill in blank

hard

Fill all three blanks to create a hash with uppercase keys and values greater than 3.

Ruby

result = ['apple', 'bat', 'cat', 'dog'].each_with_object({}) { |word, h| if [3]; h[[1]] = [2] end }

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

Aword.upcase

Bword

Cword.length > 3

Dword.size < 3

Attempts:

3 left

💡 Hint

Common Mistakes

Using word.size < 3 filters the wrong words.

Keys are uppercase words, values are the original words, filtered by length greater than 3.