Sorting a Ruby array based on part of a string

Question

I have the following array...

[ "global/20130102-001", "global/20131012-001, "country/uk/20121104-001" ]

I need to sort the array based on the numerical portion of the string. So the above would be sorted as:

[ "country/uk/20121104-001", "global/20130102-001", "global/20130112-001 ]

Is there a way to call .sort and ignore the first part of each element so I'm only sorting on the number?

Which numerical portion? The first? The second? The combination of both? — sawa
– sawa, Commented Jan 23, 2013 at 6:38

Faiz · Accepted Answer · 2013-01-23 03:55:02Z

6

Sure, just use sort_by.

  arr.sort_by do |s| 
     s.split('/').last
  end

answered Jan 23, 2013 at 3:55

Faiz

16.3k5 gold badges50 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Sergio Tulentsev · Accepted Answer · 2013-01-23 03:57:58Z

4

Yes, there's a way. You should use a #sort_by for that. Its block is passed an array element and should return element's "sortable value". In this case, we use regex to find your string of digits (you can use another logic there, of course, like splitting on a slash).

arr = [ "global/20130102-001", "global/20131012-001", "country/uk/20121104-001" ]

arr.sort_by {|el| el.scan(/\d{8}-\d{3}/)} # => ["country/uk/20121104-001", "global/20130102-001", "global/20131012-001"]

edited Jan 23, 2013 at 3:57

answered Jan 23, 2013 at 3:51

Sergio Tulentsev

231k43 gold badges381 silver badges373 bronze badges

3 Comments

user1074981 Over a year ago

This looks great but unfortunately I'm using v1.8.7

user1074981 Over a year ago

I get undefined method `sort_by!' for #<Array:0x7f7c81762410> (NoMethodError). There's no sort_by! method in the ruby doc ruby-doc.org/core-1.8.7/Array.html

Sergio Tulentsev Over a year ago

@user1074981: well, use sort_by, not sort_by!

Collectives™ on Stack Overflow

Sorting a Ruby array based on part of a string

2 Answers 2

Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related