[#77789] [Ruby trunk Feature#12012] Add Boolean method — prodis@...
Issue #12012 has been updated by Fernando Hamasaki de Amorim.
4 messages
2016/10/27
[ruby-core:77662] [Ruby trunk Bug#12851] string.gsub!(/\W/, '').downcase! returns undefined method in some (listed) cases
From:
tech@...
Date:
2016-10-18 17:21:59 UTC
List:
ruby-core #77662
Issue #12851 has been reported by Mikhail A.
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Bug #12851: string.gsub!(/\W/, '').downcase! returns undefined method in some (listed) cases
https://bugs.ruby-lang.org/issues/12851
* Author: Mikhail A
* Status: Open
* Priority: Normal
* Assignee:
* ruby -v: ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin16]
* Backport: 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN
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Found this strange issue with gsub! and downcase! methods used together for a string. Example code:
def palindrome? (str)
str.gsub!(/\W/, '').downcase!
str == str.reverse
end
puts palindrome?("Madam, I'm Adam!")
returns true. Ok! But...!
if the given string is single word:
puts palindrome?("abba")
it returns no method error.
hw1_string.rb:13:in `palindrome?': undefined method `downcase!' for nil:NilClass (NoMethodError)
from hw1_string.rb:30:in `<main>'
If the code is refactored like this:
def palindrome? (str)
str.gsub!(/\W/, '')
str.downcase!
str == str.reverse
end
than it worked ok in both cases. Why?
I'm new to ruby, and, may be still misunderstood something, but seems that is really a bug.
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