From: hanmac@...
Date: 2015-12-09T06:16:15+00:00
Subject: [ruby-core:71982] [Ruby trunk - Bug #11793] puts 'ab'.gsub('a', '\\+') - unexpected output

Issue #11793 has been updated by Hans Mackowiak.


its because how `gsub` works you need to escape the `\`

~~~ruby
puts 'ab'.gsub('a', '\\\+') #=> \+b
~~~

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Bug #11793: puts 'ab'.gsub('a', '\\+') - unexpected output
https://bugs.ruby-lang.org/issues/11793#change-55391

* Author: William Burnson
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-darwin15]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
Test case:
puts 'ab'.gsub('a', '\\\\+')

Expected output:
\\+b

Actual output:
b

The way I understand gsub(pattern, replacement) when used with two string arguments is that it will perform a literal replacement, so it is quite unexpected that substituting with \\+ removes the pattern entirely.

Doc: http://ruby-doc.org/core-2.2.3/String.html#method-i-gsub



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