Playing with Regexp in ruby

regexp.rb

# Validate data with =~ (to check it matches a regexp)

welcome = "hello guys!"
if text =~ /l{3}/
  puts "This is nice welcome message"
end

email = "[email protected]"

if email =~ /^\w+@\w+\.\w+$/
  puts "Valid email"
else
  puts "Invalid email"
end


# Extract data precisely with match (us groups with ())
full_name = "John Doe"
name_match = full_name.match(/^(?<first_name>\w+) (?<last_name>\w+)$/)
p name_match[0]
p name_match[:first_name]
p name_match[:last_name]

# match returns a MatchData object
# It is neither an Array nor a Hash
# It gives you access to the different groups () matched
# You access them with index or with symbols if you named your groups


# gsub => substitution of all texts matching a regexp
text = "hello guys "
p text.gsub(/g\w{3}/, "wagon")

# scan => global scanning of a text (less precise than match)
text_with_years = "This happened in 1986 then later on in 2001 and 2003 balblabla"
all_years_matched = text_with_years.scan(/\d{4}/)
p all_years_matched