I have an array of names
department = ['name1', 'name2', 'name3']
and an array of months
month = ['jan', 'feb', 'mar', 'etc']
I need to dynamically merge these arrays into hashes to look like this:
h = {'name1' => {'jan' => '', 'feb' => '', 'mar' => '', 'etc' => ''},
'name2' => {'jan' => '', 'feb' => '', 'mar' => '', 'etc' => ''}, 'name3' => {'jan' => '', 'feb' => '', 'mar' => '', 'etc' => ''}}
How would I go about dynamically adding keys into my hash?
Here is a way:
department
.each_with_object({}) do |name, h|
# taking an empty hash which will be holding your final output.
h[name] = month.product([""]).to_h
end
Read Array#product to know how month.product([""]) line is working. You can convert an array of array to hash using to_h.
Array#product here.
As is often the case the answer lies in the power of Enumerable:
Hash[
department.map do |d|
[
d,
Hash[
month.map do |m|
[ m, '' ]
end
]
]
end
]
There's a lot going on in here, but it boils down to a two part process, one converting the department list into a hash of hashes, and a second part to populate that with a converted month structure.
Hash[] is a handy way of converting key/value pairs into a proper Hash structure.
department = ['name1', 'name2', 'name3']
month = ['jan', 'feb', 'mar', 'etc']
month_hash = month.each_with_object({}) { |m, res| res[m] = '' }
result = department.each_with_object({}) { |name, res| res[name] = month_hash.dup }
p result
This way you could build month_hash, and then use it to build result hash, that you need
Here's how I would do it.
1) Make a Hash out of your months array
month_hash = Hash[month.map { |m| [m ,''] }]
2) Make a Hash out of your department array, inserting the newly made month hash.
result_hash = Hash[department.map { |d| [d, month_hash] }]
month = ['jan', 'feb', 'mar', 'etc']
department = ['name1', 'name2', 'name3']
month_hash = month.map {|m| [m, '']}.to_h
p department.map {|d| [d, month_hash]}.to_h
