Ruby Merging Two Arrays into One

Question

Here is my situation. I have 2 Arrays

@names = ["Tom", "Harry", "John"]

@emails = ["[e-mail]", "[e-mail]", "[e-mail]"]

I want to combine these two into some Array/Hash called @list so I can then iterate in my view something like this:

<% @list.each do |item| %>
<%= item.name %><br>
<%= item.email %><br>
<% end %>

I'm having trouble understanding how I can achieve this goal. Any thoughts?

Answer 1

Just to be different:

[@names, @emails, @urls].transpose.each do |name, email, url|
  # . . .
end

This is similar to what Array#zip does except that in this case there won't be any nil padding of short rows; if something is missing an exception will be raised.

Answer 2

Try This

Hash[@names.zip(@emails)]

You have two arrays @names = ["Tom", "Harry", "John"]

@emails = ["[e-mail]", "[e-mail]", "[e-mail]"]

@names.zip(@emails) it merge @emails to the @names associated with their index like below [["Tom", "[e-mail]"], ["Harry", "[e-mail]"], ["John", "[e-mail]"]]

Now we can convert this array into hash using Hash[@names.zip(@emails)]

Answer 3

@names  = ["Tom", "Harry", "John"]
@emails = ["[e-mail]", "[e-mail]", "[e-mail]"]

@list = @names.zip( @emails )
#=> [["Tom", "[e-mail]"], ["Harry", "[e-mail]"], ["John", "[e-mail]"]]

@list.each do |name,email|
  # When a block is passed an array you can automatically "destructure"
  # the array parts into named variables. Yay for Ruby!
  p "#{name} <#{email}>"
end
#=> "Tom <[e-mail]>"
#=> "Harry <[e-mail]>"
#=> "John <[e-mail]>"

@urls = ["yahoo.com", "ebay.com", "google.com"]

# Zipping multiple arrays together
@names.zip( @emails, @urls ).each do |name,email,url|
  p "#{name} <#{email}> :: #{url}"
end
#=> "Tom <[e-mail]> :: yahoo.com"
#=> "Harry <[e-mail]> :: ebay.com"
#=> "John <[e-mail]> :: google.com"

Answer 4

Hash[*names.zip(emails).flatten]

This will give you a hash with name => email.

Answer 5

You can use zip to zip together the two arrays and then map to create Item objects from the name-email-pairs. Assuming you have an Item class whose initialize methods accepts a hash, the code would look like this:

@list = @names.zip(@emails).map do |name, email|
  Item.new(:name => name, :email => email)
end