How to replace string in CSV::Table without destructive method

Question

I want to replace string in CSV::Table. I could replace the string by using gsub! like this:

csv = CSV.table(@csv_file)
csv[:tag].each do |tag|
  tag.gsub!('Replace1','Replace2')
  tag.gsub!('Replace3','Replace4')
end

But I prefer to use gsub with method chain

csv[:tag].each do |tag|
  tag = tag.gsub('Replace1','Replace2').
            gsub('Replace3','Replace4')
end

Unfortunately it doesn't change the csv[:tag] strings. How can I replace string in CSV::Table class without using gsub!?

Amadan · Accepted Answer · 2016-03-28 04:27:13Z

1

gsub! returns self, so you can do the same thing:

tag.gsub!('Replace1','Replace2').
    gsub!('Replace3','Replace4')

If you want to replace a string with a string you already calculated, you can use String#replace:

new_tag = tag.gsub('Replace1','Replace2').
              gsub('Replace3','Replace4')
tag.replace(new_tag)

answered Mar 28, 2016 at 4:19

Amadan

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2 Comments

probably the assignment is unneccesary

gsub! return self only when there is match, so I'll use replace method. Thanks!