Turning an array into an array of hashes using .each - arrays

Question

Given this array of String names, return an array of Hashes. Each Hash should have the keys name and id, which will represent their unique identifier in the form of an integer. The ids can start at 1 and then go up by one.
output should look like:
[{:name=>"Bruno", :id=>1},
{:name=>"Bella", :id=>2},
{:name=>"Ringo", :id=>3},
{:name=>"Spot", :id=>4},
{:name=>"Fluffy", :id=>5},
{:name=>"Snowball", :id=>6},
{:name=>"Doc", :id=>7}]
I'm trying to do something like this but I'm having trouble coming up with the right syntax and methods.
NAMES = ['Bella', 'Bruno', 'Ringo', 'Spot', 'Fluffy', 'Snowball', 'Doc']
def array_to_hash_array(names)
i = 1
NAMES.each do |name|
name = Hash.new(:name => name, :id => i)
NAMES << name
i += 1
end
return NAMES
end
puts array_to_hash_array(NAMES)

Answer 1

You can use map and with_index to return an array of Hash objects with the name and id values:
names = ['Bella', 'Bruno', 'Ringo', 'Spot', 'Fluffy', 'Snowball', 'Doc']
def array_to_hash_array(array)
array.map.with_index(1) do |name, index|
{ id: index, name: name }
end
end
p array_to_hash_array(names)
# => [{:id=>1, :name=>"Bella"}, {:id=>2, :name=>"Bruno"}, {:id=>3, :name=>"Ringo"}, {:id=>4, :name=>"Spot"}, {:id=>5, :name=>"Fluffy"}, {:id=>6, :name=>"Snowball"}, {:id=>7, :name=>"Doc"}]
I've reworked the code in your example to produce the correct output (with some notes on what was tweaked):
# variable renamed from NAMES as uppercase is meant for constants
names = ['Bella', 'Bruno', 'Ringo', 'Spot', 'Fluffy', 'Snowball', 'Doc']
def array_to_hash_array(array)
# added a result array for building up the final object to be returned
result = []
i = 1
# changed to iterate over the passed in array object
array.each do |name|
# using Hash literal instead of Hash.new since it allows us
# to specify contents of hash object directly
name = { :name => name, :id => i }
# push to result object instead of same iterated array
result << name
i += 1
end
# return built up result object
result
end
p array_to_hash_array(names)
# => [{:name=>"Bella", :id=>1}, {:name=>"Bruno", :id=>2}, {:name=>"Ringo", :id=>3}, {:name=>"Spot", :id=>4}, {:name=>"Fluffy", :id=>5}, {:name=>"Snowball", :id=>6}, {:name=>"Doc", :id=>7}]

Answer 2

Indexing an Array with #each_with_index
As Array includes the Enumerable module, you can invoke Array#each_with_index to create the data structure you want using the array index of each element of your names array with a suitable offset. For example:
names = %w[Bella Bruno Ringo Spot Fluffy Snowball Doc]
array = []
names.each_with_index do |name, index|
array << { name: name, id: index.succ }
end
Note the use of Integer#succ, which is used to offset the index by one. Since Ruby arrays are zero-indexed, you need to increment the index value passed in by #each_with_index to get the numbering the way you want.
You can pretty-print the array with Kernel#pp (e.g. pp array) to verify the results:
[{:name=>"Bella", :id=>1},
{:name=>"Bruno", :id=>2},
{:name=>"Ringo", :id=>3},
{:name=>"Spot", :id=>4},
{:name=>"Fluffy", :id=>5},
{:name=>"Snowball", :id=>6},
{:name=>"Doc", :id=>7}]
Note on Hash Key Ordering
As you can see, this populated the array of hashes the way you wanted, and in the specific format you're looking for. However, it's important to remember that while the order of keys in a hash are kept in insertion order in mainline Ruby, you shouldn't really rely on that behavior. Conceptually, hashes are unordered, so:
[{:id=>1, :name=>"Bella"},
{:id=>2, :name=>"Bruno"},
{:id=>3, :name=>"Ringo"},
{:id=>4, :name=>"Spot"},
{:id=>5, :name=>"Fluffy"},
{:id=>6, :name=>"Snowball"},
{:id=>7, :name=>"Doc"}] ==
[{:name=>"Bella", :id=>1},
{:name=>"Bruno", :id=>2},
{:name=>"Ringo", :id=>3},
{:name=>"Spot", :id=>4},
{:name=>"Fluffy", :id=>5},
{:name=>"Snowball", :id=>6},
{:name=>"Doc", :id=>7}]
#=> true

Answer 3

You can try it
names.each_with_index.map { |x,i| {name: x, id: i+1} }

Answer 4

names = ['Bella', 'Bruno', 'Ringo', 'Spot', 'Fluffy', 'Snowball', 'Doc']
enum = 1.step
#=> (1.step)
names.map { |name| { name: name, id: enum.next } }
#=> [{:name=>"Bella", :id=>1}, {:name=>"Bruno", :id=>2},
# {:name=>"Ringo", :id=>3}, {:name=>"Spot", :id=>4},
# {:name=>"Fluffy", :id=>5}, {:name=>"Snowball", :id=>6},
# {:name=>"Doc", :id=>7}]
See Numeric#step and Enumerator#next.

Answer 5

You could zip (Enumerable#zip) to an endless range (beginless-endless-range) then map to the desired hash:
ary = ['Bella', 'Bruno', 'Ringo', 'Spot', 'Fluffy', 'Snowball', 'Doc']
ary.zip(1..).map { |name, id| {name: name, id: id} }