Mercurial > repos > other > SevenLanguagesInSevenWeeks
annotate 1-Ruby/arrays.rb @ 103:98be775c533c default tip
An odd "non-determinism" example from StackOverflow
It is clever, but doesn't make much sense as to how it gets its results
| author | IBBoard <dev@ibboard.co.uk> |
|---|---|
| date | Sun, 14 Jul 2019 13:44:13 +0100 |
| parents | 8d46064c9afc |
| children |
| rev | line source |
|---|---|
| 14 | 1 #! /usr/bin/env ruby |
| 2 | |
| 3 animals = ['lions', 'tigers', 'bears'] | |
| 4 | |
| 5 # Default "puts" for array is one element per line | |
| 6 puts animals | |
| 7 | |
| 8 puts "Accessing undefined indexes gives nil" if animals[10] == nil | |
| 9 puts "Negative indexes also work (like Python): -1 = #{animals[-1]}" | |
| 10 puts "And you get slices/ranges: 1..2 = #{animals[1..2]}" | |
| 11 puts "1..2 is even an object: #{(1..2).class}" | |
| 12 puts "and indexers are methods: [1].methods.include?(:[]) = #{[1].methods.include?(:[])}" | |
| 13 # Note: we're using v1.9+ syntax - previously it was "….include?('[]')" | |
| 14 puts "as is assignment to an array! [1].methods.include?(:[]=) = #{[1].methods.include?(:[]=)}" | |
| 15 puts "" | |
| 16 puts "All funky non-ASCII methods for arrays:" | |
|
16
8d46064c9afc
Be a nice Ruby user and follow block convention for do/end vs {}
IBBoard <dev@ibboard.co.uk>
parents:
14
diff
changeset
|
17 [].methods.each do |method| |
| 14 | 18 if method !~ /[a-z]/ |
| 19 puts method | |
| 20 end | |
|
16
8d46064c9afc
Be a nice Ruby user and follow block convention for do/end vs {}
IBBoard <dev@ibboard.co.uk>
parents:
14
diff
changeset
|
21 end |
| 14 | 22 |
| 23 puts "" | |
| 24 puts "Arrays are also stacks with push() and pop() methods!" |