I have a hash in which I want to use the values as keys in a new Hash which contains a count of how many times that item appeared as a value in the original hash.
So I use:
hashA.keys.each do |i|
puts hashA[i]
end
Example output:
0
1
1
2
0
1
1
And I want the new Hash to be the following:
{ 0 => 2, 1 => 4, 2 => 1 }
counts = hashA.values.inject(Hash.new(0)) do |collection, value|
collection[value] +=1
collection
end
TL;DR: hashA.values.inject(Hash.new(0)) { |m, n| m[n] += 1; m }
hashA.values.inject(Hash.new(0)) { |m, n| m[n] += 1; m }
> hashA = { a: 0, b: 1, c: 1, d: 2, e: 0, f: 1, g: 1 }
=> {:a=>0, :b=>1, :c=>1, :d=>2, :e=>0, :f=>1, :g=>1}
> hashCounts = hashA.values.inject(Hash.new(0)) { |m, n| m[n] += 1; m }
=> {0=>2, 1=>4, 2=>1}
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