String concatenation in Ruby

Question

I am looking for a more elegant way of concatenating strings in Ruby.

I have the following line:

source = \"#{ROOT_DIR}/\" << project <<          


        

Answer 1

Situation matters, for example:

# this will not work
output = ''

Users.all.each do |user|
  output + "#{user.email}\n"
end
# the output will be ''
puts output

# this will do the job
output = ''

Users.all.each do |user|
  output << "#{user.email}\n"
end
# will get the desired output
puts output

In the first example, concatenating with + operator will not update the output object,however, in the second example, the << operator will update the output object with each iteration. So, for the above type of situation, << is better.