I have an array and I want to convert it to a hash. I want the array elements to be keys, and all values to be the same.
Here is my code:
h = Hash.new
myarr.each do |elem|
h[elem] = 1
end
One alternative would be the following. I don't think it's very different from the solution above.
h = Hash[ *myarr.collect { |elem| [elem, 1] }.flatten ]
Is there a better way I can do this?
The code OP wrote, can also be written as :-
a = %w(a b c d)
Hash[a.each_with_object(1).to_a]
# => {"a"=>1, "b"=>1, "c"=>1, "d"=>1}
And if you have Ruby version >= 2.1, then
a.each_with_object(1).to_h
# => {"a"=>1, "b"=>1, "c"=>1, "d"=>1}
First of all, Hash[] is quite happy to get an array-of-arrays so you can toss out the splat and flatten and just say this:
h = Hash[myarr.map { |e| [ e, 1 ] }]
I suppose you could use each_with_object instead:
h = myarr.each_with_object({}) { |e, h| h[e] = 1 }
Another option would be to zip your myarr with an appropriate array of 1s and then feed that to Hash[]:
h = Hash[myarr.zip([1] * myarr.length)]
I'd probably use the first one though.
If you are using Ruby 2.1:
myarr.map{|e| [e,1]}.to_h
Another clever way (from comment by @ArupRakshit):
myarr.product([1]).to_h
Here is another option, using cycle:
Hash[a.zip([1].cycle)]
a.each_with_object({}){|e, h| h[e] = 1}
Hash[] arguments and I took the time to include other solutions.