Ruby style guide essentials - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Ruby code snippet?

Consider the following Ruby code. What will it print?

Ruby

def greet(name)
  puts "Hello, #{name.capitalize}!"
end

greet("alice")

A Hello, Alice!

B Hello, alice!

C hello, Alice!

D HELLO, ALICE!

💡 Hint

Look at the capitalize method and how it changes the string.

The capitalize method makes the first letter uppercase and the rest lowercase. So "alice" becomes "Alice".

🧠 Conceptual

intermediate

Which is the preferred Ruby style for method names?

According to Ruby style guide essentials, which method name style is preferred?

A PascalCaseMethod

B snake_case_method

C camelCaseMethod

D kebab-case-method

💡 Hint

Think about how Ruby methods are usually named to improve readability.

Ruby style guide recommends using snake_case for method names for clarity and consistency.

🔧 Debug

advanced

What error does this Ruby code raise?

Examine the code below. What error will it raise when run?

Ruby

numbers = [1, 2, 3]
puts numbers[3].to_s

A NilClass error

B IndexError

C No error, prints empty string

D NoMethodError

💡 Hint

What does Ruby return when accessing an array index that is out of range?

Accessing an out-of-range index returns nil. Calling to_s on nil returns an empty string, so no error occurs.

📝 Syntax

advanced

Which option correctly defines a Ruby class with an initialize method?

Choose the correct Ruby syntax for defining a class Person with an initialize method that takes a name parameter.

A

class Person
  def initialize(name)
    @name = name
  end
end

B

class Person
  def initialize name
    name = @name
  end
end

C

class Person
  def initialize(name):
    @name = name
  end
end

D

class Person
  def initialize(name)
    name = @name
end

💡 Hint

Remember Ruby uses def and end to define methods and classes, and instance variables start with @.

Option A correctly defines the class and initialize method, assigns the parameter to an instance variable, and closes all blocks properly.

🚀 Application

expert

How many key-value pairs are in the resulting hash?

What is the number of key-value pairs in the hash created by this Ruby code?

Ruby

hash = { a: 1, b: 2, a: 3, c: 4 }

A 4

B 1

C 2

D 3

💡 Hint

Consider what happens when a hash has duplicate keys.

In Ruby, if a hash has duplicate keys, the last value for that key overwrites previous ones. So keys are :a, :b, :c with values 3, 2, 4 respectively, total 3 pairs.