How to Automatically Add odd_or_even in a Loop

When working with Ruby loops, there may be times when you need to distinguish between odd and even elements. While you can utilize the ActiveSupport cycle helper in Ruby to achieve this, it may be unnecessary in simpler scripting tools. This article will guide you on how to add the odd_or_even distinction automatically in a loop, even without the cycle helper.

Without relying on the cycle helper, one approach is to extend the Array class and add an enumerable method called each_with_index_parity. Here’s an example implementation:

class Array
  def each_with_index_parity
    self.each_with_index do |entry, index|
      yield(entry, index, index % 2 == 0 ? :even : :odd)
    end
  end
end

With this extension, you can now utilize the each_with_index_parity method. Here’s an example of how you can use it:

@records = ('a'..'z').to_a
@records.each_with_index_parity do |el, index, parity|
  puts "#{el} #{index} #{parity}"
end

By implementing this extension, you can easily iterate over the elements of the @records array and obtain the element, its index, and its parity (whether it’s odd or even).

Alternatively, if you prefer not to define methods in a built-in class like Array, you can achieve the same result by iterating over the array using the each_with_index method and calculating the parity within the loop. Here’s an example:

@records = ('a'..'z').to_a
@records.each_with_index do |el, index|
  parity = index.even? ? :even : :odd
  puts "#{el} #{index} #{parity}"
end

In this case, the parity calculation is performed within the loop code itself.

Both approaches provide a way to distinguish between odd and even elements in a loop. Choose the one that best fits your needs and the requirements of your scripting tool.

Remember, there are multiple ways to solve this problem, and these examples provide two viable approaches to achieve the desired outcome.