> On 2018-May-15, at 14:39 , Walter Lee Davis <wa...@wdstudio.com> wrote:
>
> If you can put those into a hash, then you can look up values by their keys,
> or vice-versa. Just call STATE_TYPES.to_h and then you have a hash where the
> names are the keys, and the abbreviations are the values. If you call
> STATE_TYPES.map(&:reverse).to_h, you will have the abbreviations as keys and
> the names as values. In either case, you could then use index notation to get
> a given key's value:
>
> STATE_TYPES.to_h['Arizona']
> => 'AZ'
>
> STATE_TYPES.map(&:reverse).to_h['AZ']
> => 'Arizona'
>
> You don't need to call map or to_h every time, just make a new constant and
> use it over and over:
>
> STATES = STATE_TYPE.map(&:reverse).to_h
>
> STATES['AZ']
> => 'Arizona'
>
> Walter
Or you can take advantage of some other Ruby behavior:
The Hash[] constructor which will build a Hash from an Array of pairs (i.e.,
Arrays of two elements)
Hash#invert which returns a new hash with the values and keys swapped.
[3] pry(main)> STATE_TYPES = [ ['Alabama','AL'], ['Arizona','AZ'],
['Ohio','OH'] ]
=> [["Alabama", "AL"], ["Arizona", "AZ"], ["Ohio", "OH"]]
[4] pry(main)> Hash[STATE_TYPES].invert
=> {"AL"=>"Alabama", "AZ"=>"Arizona", "OH"=>"Ohio"}
[5] pry(main)> Hash[STATE_TYPES].invert['OH']
=> "Ohio"
You might also want to look up Array#assoc and Array#rassoc which will operate
directly on your array of pairs:
[6] pry(main)> STATE_TYPES.rassoc('OH')
=> ["Ohio", "OH"]
[7] pry(main)> STATE_TYPES.rassoc('OH').first
=> "Ohio"
-Rob
>
>> On May 15, 2018, at 1:10 PM, fugee ohu <fugee...@gmail.com> wrote:
>>
>> I have an array of US States that looks like STATE_TYPES = [
>> ['Alabama', 'AL'], ... ]
>> In views I need to display the State name from the value I have in the
>> database, it's abbreviation
>>
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