Zane Bliss

Ruby Tips! Replace multiple characters in a string with `gsub` hash 🚀

Did you know that when using #gsub on a string, you can match and replace multiple characters at a time using a hash argument? According to the #gsub Ruby-Doc.org documentation:

gsub(pattern, replacement) → new_string

If argument replacement is a hash, and pattern matches one of its keys, the replacing string is the value for that key

Suppose you have a log message you would like to format and clean up.

Before

'[Error]: Uh oh, something went wrong!'

After

'Uh oh, something went wrong! (error)'

We can write a simple method that formats our log.

REGEX_PATTERN = /\[|\]/

def reformat_log(log)
  log_level, message = log.split(':')

  formatted_log_level = log_level.gsub(REGEX_PATTERN, '[' => '(', ']' => ')')

  message.strip << " #{formatted_log_level.downcase}"
end

Then, using IRB, we get the following.

irb(main):009:0> reformat_log('[Error]: Uh oh, something went wrong!')
=> "Uh oh, something went wrong! (error)"

Thanks for reading! What Ruby tricks have you been using recently?