How do I select a random item from an array in ruby (not rails)

Question

I have an array of countries:

@countries = ["Canada", "Denmark", "Germany", "Isle of Man", "Namibia", "Qatar", "South Africa",  "United Kingdom","United States"]

And am building some random data for testing like this:

@test = [{ :name   => "AAA -"+Faker::Name.name,  :country => @countries.???? ....}]

How do I get a random value from the @countries hash?

@countries.rand(mlen)

does not work and returns NoMethodError: private methodrand' called for #`.

For future reference, you should be referring to your data structure of countries as an `array` not a `hash`. — Andrew Hubbs, Dec 06 '12 at 23:44
It's good to be familiar with all the methods in [Array](http://apidock.com/ruby/Array) and [Enumerable](http://apidock.com/ruby/Enumerable). It will save you a lot of effort and make your programs shorter! — Mark Thomas, Dec 07 '12 at 01:23

score 34 · Accepted Answer · answered Dec 06 '12 at 23:34

34

use Array#sample:

@countries = ["Canada", "Denmark", "Germany", "Isle of Man", "Namibia", "Qatar", "South Africa",  "United Kingdom","United States"]

random_country = @countries.sample
# => "Canada"

random_country = @countries.sample
# => "United Kingdom"

answered Dec 06 '12 at 23:34

Works great thanks. I tried rand but this is a private method. Ruby has many hidden Gems. – Gary Dec 06 '12 at 23:40
For Ruby 1.8.7, it's [Array#choice](http://ruby-doc.org/core-1.8.7/Array.html#method-i-choice) – robd Mar 07 '14 at 15:08

score 4 · Answer 2 · edited Dec 07 '12 at 00:09

4

You could also use random_country = @countries.shuffle.first.

edited Dec 07 '12 at 00:09

McGarnagle

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answered Dec 06 '12 at 23:45

cluv

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How do I select a random item from an array in ruby (not rails)

2 Answers2