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Ruby Ruby Booleans Build a Simple Todo List Program Returning Boolean Values: Part 2

King Penson II
King Penson II
16,413 Points
Posted by King Penson II
King Penson II
16,413 Points

I am completely stumped at this Contains? method

I've tried everything to if/else statements to the current code I have now. I fooled around with the include? method and got it to return a boolean in irb, I just can't figure out this challenge.

todo_list.rb 
class TodoList
  attr_reader :name, :todo_items

  def initialize(name)
    @name = name
    @todo_items = []
  end

  def add_item(name)
    todo_items.push(TodoItem.new(name))
  end

  def contains?(name)
    todo_items.include?()
  end

  def find_index(name)
    index = 0
    found = false
        todo_items.each do |item|
      found = true if item.name == name
      break if found
      index += 1
    end
    if found
      return index
    else
      return nil
    end
  end
end

3 Answers

William Li
PLUS
William Li
Courses Plus Student 26,868 Points
William Li
William Li
Courses Plus Student 26,868 Points

Or, you can approach it this way, make use of the find_index method

  def contains?(name)
    !!find_index(name)   # convert find_index(name) to boolean value
  end
King Penson II
King Penson II
16,413 Points
King Penson II
King Penson II
16,413 Points

Sorry for the late response, this solution worked. I honestly feel like I was trying too hard.

Maciej Czuchnowski
Maciej Czuchnowski
36,441 Points
Maciej Czuchnowski
Maciej Czuchnowski
36,441 Points

You could use the find_index method and do something like this:

  def contains?(name)
    if find_index(name)
      return true
    else
      return false
    end
  end
Paul Stettnisch
Paul Stettnisch
10,712 Points
Paul Stettnisch
Paul Stettnisch
10,712 Points

Thank you Maciej. While the other two responses seem like they would work, they are not what was taught in the previous video. I believe this solution is what students can be expected to be able to use this point in their learning.

Salman Akram
PLUS
Salman Akram
Courses Plus Student 40,065 Points
Salman Akram
Salman Akram
Courses Plus Student 40,065 Points

Hi King,

Other way you can try is .any? method to see if the block returns a value of true with the name arguments. 

  def contains?(name)
    todo_items.any? { |item_array| item_array.name==name }
  end

More information on Ruby Doc & Block examples

Hope that helps.