Class.new for dynamic class creation in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new class dynamically using Class.new.

Ruby

MyClass = [1] do
  def greet
    'Hello!'
  end
end

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AClass.new

Bclass.new

CNewClass

Dclass.New

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'class.new' instead of 'Class.new'.

Trying to use 'NewClass' as a method.

Using dot notation incorrectly like 'class.New'.

Use Class.new to create a new class dynamically in Ruby.

2fill in blank

medium

Complete the code to create an instance of the dynamically created class.

Ruby

obj = MyClass.[1]

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Amake

Bcreate

Cnew

Dbuild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'create' or 'build' which are not Ruby methods for instantiation.

Forgetting to call a method and just writing 'MyClass'.

Use .new to create an instance of a class in Ruby.

3fill in blank

hard

Fix the error in the code to define a method inside the dynamically created class.

Ruby

MyClass = Class.new do
  def [1]
    'Hi there'
  end
end

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Asay_hello

BsayHello

CSayHello

Dsay-hello

Attempts:

3 left

💡 Hint

Common Mistakes

Using camelCase like 'sayHello' which is not Ruby style.

Using capitalized method names which are constants.

Using hyphens which are invalid in method names.

Method names in Ruby should be lowercase with underscores, so say_hello is correct.

4fill in blank

hard

Fill both blanks to create a dynamic class with an initialize method that sets a name attribute.

Ruby

Person = Class.new do
  def [1](name)
    @[2] = name
  end
end

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Ainitialize

Bname

Cage

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'init' instead of 'initialize'.

Using a wrong instance variable name like '@age' when parameter is 'name'.

The constructor method in Ruby is initialize, and instance variables start with @ followed by the attribute name like @name.

5fill in blank

hard

Fill all three blanks to create a dynamic class with an attribute reader and a method that returns a greeting with the name.

Ruby

User = Class.new do
  attr_reader :[1]

  def initialize([2])
    @[3] = [2]
  end

  def greet
    "Hello, #{@[1]!"
  end
end

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Aname

Busername

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing different names for attribute reader and instance variables.

Using undefined variables in the greet method.

Use name consistently: attr_reader :name, initialize(name), @name = name. The greet method uses @name.