Getting a 'Type Error' When Iterating Through a Ruby Array

Question

I am getting the following error:

Can't convert String into Integer (TypeError)

It is happening on this line:

if new_animal != animals[i]

Why is this happening?

animals = ['rhino', 'giraffe', 'cat', 'dolphin', 'turtle']

puts 'Enter the new animal:'
new_animal = gets.chomp

empty_array = []

animals.each do |i|
  if new_animal != animals[i]
    empty_array << i
  end
end

Answer 1

animals.each do |i| is not doing what you think it does. i then is the actual strings (animal names). So if you iterate through and use an animal name as an array accessor in animals[i] it is not an integer and cannot be converted to one.

animals.each do |animal|
    empty_array << animal if new_animal != animal
end

is the correct way to do it.

In Ruby if you want an iterator integer, you can do each_index and that will give you the integer position. each_index is not used too much in Ruby though, that is why I refactored your code to what I posted.

Or you can just make it one line of code and do:

animals.index(new_animal) 

which will return nil if it is not in the array or the fixnum position if it is in the array

Answer 2

Michael got it right... when you run this code

animals = ['rhino', 'giraffe', 'cat', 'dolphin', 'turtle']
animals.each {|i| puts i}

you get:

rhino
giraffe
cat
dolphin
turtle

so "i" does not refer to what you expect it to refer to...