getting the date out of a string in an array then sorting those strings by the date

Question

I need help getting the date out of strings in an array then sorting those strings by the date. This is the array with each strings index number.

array = [
[0] "Bonk  Radek  S  Male  Green  6/3/1978",
[1] "Bouillon  Francis  G  Male  Blue  6/3/1975",
[2] "Smith  Steve  D  Male  Red  3/3/1985"
]

I want to re-arange and sort each string by the date in ascending order. Anyone have a clean and simple way of doing this in ruby?

Answer 1

You can do

require 'date'

array = [
  "Bonk  Radek  S  Male  Green  6/3/1978",
  "Bouillon  Francis  G  Male  Blue  6/3/1975",
  "Smith  Steve  D  Male  Red  3/3/1985"
]

array.map { |str| str[/\d+\/\d+\/\d+/] }
# => ["6/3/1978", "6/3/1975", "3/3/1985"]
array.map { |str| Date.strptime(str[/\d+\/\d+\/\d+/], "%d/%m/%Y") }
# => [#<Date: 1978-03-06 ((2443574j,0s,0n),+0s,2299161j)>,
#     #<Date: 1975-03-06 ((2442478j,0s,0n),+0s,2299161j)>,
#     #<Date: 1985-03-03 ((2446128j,0s,0n),+0s,2299161j)>]
# to sort
array.sort_by { |str| Date.strptime(str[/\d+\/\d+\/\d+/], "%d/%m/%Y") }
# => ["Bouillon  Francis  G  Male  Blue  6/3/1975",
#     "Bonk  Radek  S  Male  Green  6/3/1978",
#     "Smith  Steve  D  Male  Red  3/3/1985"]

Answer 2

You could write it like so:

array = [
       "Bonk  Radek  S  Male  Green  6/3/1978",
  "Bouillon  Francis  G  Male  Blue  6/3/1975",
    "Thornton Billy-Bob Male Purple 11/3/1985",
        "Smith  Steve  D  Male  Red  3/3/1985",
          "Dillon Matt Male Orange 14/11/1984"
]

def year_month_day(line)
  d, m, y =
    line.scan(/([1-9]|[1-3]\d)\/([1-9]|1[0-2])\/([12]\d{3})/).flatten
  [y.to_i, m.to_i, d.to_i]
end

array.sort_by { |line| year_month_day(line) }
  # => ["Bouillon  Francis  G  Male  Blue  6/3/1975",
  #          "Bonk  Radek  S  Male  Green  6/3/1978",
  #             "Dillon Matt Male Orange 14/11/1984",
  #           "Smith  Steve  D  Male  Red  3/3/1985",
  #       "Thornton Billy-Bob Male Purple 11/3/1985"]