Return a unique array of values from array of hashes

Question

I have an array @contacts of hashes, each of which has the following keys:

:full_name
:city
:state
:email

How would I iterate through the array to return the :city values uniquely? Below is my best attempt

@contacts.uniq {|hash| hash[:city]}

if this is rails, you could do it at the db layer...

rogerdpack
– rogerdpack

2013-01-27 05:08:23 +00:00
Commented Jan 27, 2013 at 5:08 — rogerdpack
– rogerdpack, Commented Jan 27, 2013 at 5:08

DigitalRoss · Accepted Answer · 2013-01-27 04:38:00Z

2

@contacts.map { |k| k[:city] }.uniq

answered Jan 27, 2013 at 4:38

DigitalRoss

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2 Comments

NealR Over a year ago

This worked, thanks. Does this mean that any .method added to the block of code is executed when whatever conditions inside that block return a value/true?

DigitalRoss Over a year ago

No, it's equivalent to (t = @contacts.map { |k| k[:city] }; t.uniq)

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