Programming Ruby 3rd _new topics for me

• regexp: \p: encoding-aware
  
• regexp: &&: [a-z]&&[^aeiou] means match a to z but vowels
  
• regexp: named group: /(?<word>\w)\k<word>/ #repeat same words
  
• regexp: named group: /(?<hour>\d\d)/;"Hour is #{hour} #it also can refer after as param
  
• regexp: sub can get a hash as the replacement param
  
• regexp: 'a\b\b'.gsub(/\\/, '\&\&') # => "a\\b\\c"
  
• method: pass all params: def initialize(*); super; end
  
• method argument with splat: method_one(*[1,2], 3, *(4..8))