[Ruby] 1-D Array to Hash

在實作寄信功能時，需要把一維陣列轉成hash，於是思維還沒轉成ruby的我就寫下這段很初學者的code

原來的code，為了建立mail_list這個hash，花了6行程式碼

app/controllers/goals_controller.rb

class GoalsController < ApplicationController
	...略
  def generate_json_params
    mail_list = {}
    count = 0
    for email in @goal.shared_mails
      mail_list[count.to_s] = email.mail_addr
      count+=1
    end

    h = JSON.generate({ 'owner' => @goal.owner.name,
                        'goal' => @goal.title,
                        'complete_date' => @goal.complete_date,
                        'email' => mail_list })
  end
end

使用Ruby內建的Hash[]可將陣列轉成Hash，再搭配with_index以index當key，一行搞定！

app/controllers/goals_controller.rb

class GoalsController < ApplicationController	
  ...略
  def generate_json_params    
    mail_list = Hash[ @goal.shared_mails.map.with_index {|x, i| [i, x.mail_addr]}]
    h = JSON.generate({ 'owner' => @goal.owner.name,
                        'goal' => @goal.title,
                        'complete_date' => @goal.complete_date,
                        'email' => mail_list })
  end
end

(沒想到重構一個function居然可以寫3篇文章 XD)

參考來源：
ihower blog文章