easyarrays push map select
What is the value of `nums` after this code runs?
nums = [1, 2, 3]
doubled = nums.map { |n| n * 2 }
p numswhy this works
Built for Ruby mastery, not memorisation.
Every question is hand-checked, every answer comes with an explanation, and your progress builds into a clear picture of where you stand.
The snippet is on the page
Every Ruby question shows its code before you answer, so you are reading real Ruby, not a description of it.
A written explanation, always
Once you attempt a question you get the reasoning, not just a tick. That matters most on Ruby, where method lookup through modules and prepend, blocks versus procs versus lambdas and their return behaviour, method_missing, mutation of frozen objects, and the singleton class.
Your weak topics, named
Progress is tracked per topic across the 60 Ruby topics, so revision points at the gaps instead of the whole list.
faq
Things people ask.
How many Ruby MCQs are on Journey Uncommon?
557 Ruby questions right now: 50 easy, 247 medium and 260 hard. That number is read straight from the question table when this page is built, so it is never a rounded marketing figure.
Do I need an account to read the Ruby questions?
No. Every Ruby question, including its code snippet, its difficulty and its topic, is readable without signing in. You need a free account only to submit an answer, see which option is correct, and read the worked explanation. We keep it that way so the platform stays honest about what you actually got right.
What do Ruby interviewers actually test?
Method lookup through modules and prepend, blocks versus procs versus lambdas and their return behaviour, method_missing, mutation of frozen objects, and the singleton class.
Which Ruby topics are covered?
60 distinct topics are tagged on the Ruby questions, including method_missing and respond_to_missing, method lookup and ancestors, method_missing dispatch internals, Proc vs lambda return and arity, mark-sweep and GC.compact, Comparable and spaceship. The topic labels come from the questions themselves, so the list matches what you will actually be asked.
Is Ruby practice free?
Yes. Reading is free and unlimited. A free account unlocks answering, explanations and progress tracking. Pro (₹199 per month) adds AI explanations and AI-graded guesstimates on top; it is not needed to practise Ruby MCQs.
Where is Ruby used in real jobs?
Rails product companies, internal tooling, and startups that value shipping speed.
What a Ruby question here actually looks like
These are 12 of the 557 Ruby questions in the library, pulled live from the question table. The snippet, the difficulty and the topic are all here. The answer options and the explanation are not. Those need a free account.
Method lookup through modules and prepend, blocks versus procs versus lambdas and their return behaviour, method_missing, mutation of frozen objects, and the singleton class.
Sample Ruby MCQs
easyhashes literals and fetch
Given `h = { a: 1, b: 2 }`, what does `h.fetch(:c)` do?
h = { a: 1, b: 2 }
h.fetch(:c)mediummethod_missing and respond_to_missing
A class defines method_missing to handle any call, but does NOT define respond_to_missing?. What does calling obj.method(:anything) return for a name the class handles only via method_missing?
class Ghost
def method_missing(name, *args)
"ghost: #{name}"
end
end
g = Ghost.new
puts g.anything # works
m = g.method(:anything) # ???mediumdefine_method
Methods are generated in a loop with define_method. For `Roles.new(:editor)`, what do `admin?`, `editor?`, and `viewer?` return?
class Roles
%i[admin editor viewer].each do |role|
define_method("#{role}?") { @role == role }
end
def initialize(r) = @role = r
end
u = Roles.new(:editor)
[u.admin?, u.editor?, u.viewer?]hardfrozen string dedup
In CRuby 3.x, both expressions are evaluated repeatedly at runtime. Which statement correctly explains why one form deduplicates equal-content strings into a single shared frozen object and the other does not?
a = "pre#{ENV['X']}".freeze
b = "pre#{ENV['X']}".freeze
c = -"pre#{ENV['X']}"
d = -"pre#{ENV['X']}"
# Assume ENV['X'] is unset, so all four have equal content.easystring interpolation and methods
What does this expression return?
p "ab" * 3mediumEnumerable and custom each
A class includes `Enumerable` and defines `each`. What does calling `map` without a block return?
class Bag
include Enumerable
def initialize(*items); @items = items; end
def each; @items.each { |i| yield i }; end
end
puts Bag.new(1, 2, 3).map.classeasyarrays push map select
What does this code output?
p [1, nil, 2, false, 3].compacteasytimes upto each_with_index
How many times does this loop print "hi"?
0.times do
puts "hi"
endeasytruthiness only nil false falsy
What does this method return when called as describe(nil)?
def describe(x)
if x.nil?
"got nil"
elsif x == false
"got false"
else
"got something"
end
endeasyclasses initialize attr_accessor
What is printed?
class User
attr_accessor :name
def initialize(n)
name = n
end
end
puts "Hi, #{User.new('Sam').name}"easystring interpolation and methods
What does this string interpolation produce?
name = "Sam"
puts "Hi #{name.upcase}!"Sign in to answer
Everything above is free to read. Answering needs a free account.
We keep the correct answer, the explanation and the scoring behind sign-in so the platform stays honest, which is why the correct option and the worked explanation for every Ruby question stay behind a free account. Signing in is free and takes a few seconds.
Where Ruby shows up
Rails product companies, internal tooling, and startups that value shipping speed.