find a hash key for specific array-as-value

Question

Given a hash of arrays, I need to get the key for which the first element of the array is minimal.

For instance, for:

h = { :a => [8,9,1], :b => [7,2,3], :c => [1,7,3] }

I'd like to get :c as result because 1 is the min of [8,7,1]

How can I do this elegantly?

xdazz · Accepted Answer · 2012-09-27 15:17:42Z

3

h.key(h.values.min_by &:first)

answered Sep 27, 2012 at 15:17

xdazz

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2 Comments

you should also let your first (longer) solution

@JCLL Find the min value don't need to sort, so i prefer min_by.

Eureka · Accepted Answer · 2012-09-27 15:22:55Z

0

h.sort_by { |k,v| v[0] }[0][0]
# or (equivalent)
h.sort_by { |k,v| v.first }.first.first

By using the default array comparator, this can even be shortened to:

h.sort_by { |k,v| v }[0][0]

answered Sep 27, 2012 at 15:22

Eureka

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