Weird backslash substitution in Ruby

Question

I don\'t understand this Ruby code:

>> puts \'\\\\ <- single backslash\'
# \\ <- single backslash

>> puts \'\\\\ <- 2x a, because 2 bac         


        

Answer 1

This is an issue because backslash (\) serves as an escape character for Regexps and Strings. You could do use the special variable \& to reduce the number backslashes in the gsub replacement string.

foo.gsub(/\\/,'\&\&\&') #for some string foo replace each \ with \\\

EDIT: I should mention that the value of \& is from a Regexp match, in this case a single backslash.

Also, I thought that there was a special way to create a string that disabled the escape character, but apparently not. None of these will produce two slashes:

puts "\\"
puts '\\'
puts %q{\\}
puts %Q{\\}
puts """\\"""
puts '''\\'''
puts <