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ruby-on-railsrubyhashmaxby

Pushing max hash key-values into an array in Ruby?

I have a hash called count, defined as count = {4=>2, 5=>3, 6=>3, 7=>1}.

I want to take the max value, and then push the key that corresponds to that value into an array, so I do this:

array = []
array.push(count.max_by{|k,v| v}[0])

=>> [5]

However, 6 also has the value 3, which is another maximum value. How do I push this value into the array so I get [5,6] instead of just [5]?

Solution

  • This is the way to choose the max values of the hash:

    count.values.max
=> 3

    Use the select method on the hash:

    count.select{ |k, v| v == count.values.max }
 => {5=>3, 6=>3}

    Get the keys:

    count.select{ |k, v| v == count.values.max }.keys
 => [5, 6]

    And finally assign to an array:

    array = count.select{ |k, v| v == count.values.max }.keys