regular_expressions.rb

# Determine whether a string contains a Social Security number.
def has_ssn?(string)
  true if string =~ /\d{3}-\d{2}-\d{4}/
end
 
puts "has_ssn? returns true if it has what looks like a SSN"
puts has_ssn?("please don't share this: 234-60-1422") == true
 
puts "has_ssn? returns false if it doesn't have a SSN"
puts has_ssn?("please confirm your identity: XXX-XX-1422") == false
 
 
# Return the Social Security number from a string.
def grab_ssn(string)
  if string =~ /(\d{3}-\d{2}-\d{4})/
    # $1 is the regex group in paranethesis above
    ssn = $1
  end
end
 
 
puts "grab_ssn returns an SSN if the string has an SSN"
puts grab_ssn("please don't share this: 234-60-1422") == "234-60-1422"
 
puts "grab_ssn returns nil if it doesn't have a SSN"
puts grab_ssn("please confirm your identity: XXX-XX-1422") == nil
 
 
# Return all of the Social Security numbers from a string.
def grab_all_ssns(string)
  results = []
  ssns = string.split(" ")
  ssns.each do |ssn|
    if grab_ssn(ssn)
      results << grab_ssn(ssn)
    end
  end
  results
end
 
puts "grab_all_ssns returns all SSNs if the string has any SSNs"
puts grab_all_ssns("234-60-1422, 350-80-0744, 013-60-8762") == ["234-60-1422", "350-80-0744", "013-60-8762"]
 
puts "grab_all_ssns returns an empty Array if it doesn't have any SSNs"
puts grab_all_ssns("please confirm your identity: XXX-XX-1422") == []
 
 
# Obfuscate all of the Social Security numbers in a string. Example: XXX-XX-4430.
def hide_all_ssns(string)
  

  results = grab_all_ssns(string)
  results.each do |ssn|
    ssn.gsub!(/\d{3}-\d{2}/, 'XXX-XX')
  end
  if results.empty?
    return string
  else
    results.join(", ")
  end
end
 
puts "hide_all_ssns obfuscates any SSNs in the string"
puts hide_all_ssns("234-60-1422, 350-80-0744, 013-60-8762") == "XXX-XX-1422, XXX-XX-0744, XXX-XX-8762"
 
puts "hide_all_ssns does not alter a string without SSNs in it"
string = "please confirm your identity: XXX-XX-1422"
puts hide_all_ssns(string) == string
 
 
# Ensure all of the Social Security numbers use dashes for delimiters.
# Example: 480.01.4430 and 480014430 would both be 480-01-4430.
def format_ssns(string)
  array = string.split(" ")
  results = []
  array.each do |ssn|
    ssn.gsub!(/\W/, "")
    results << "#{ssn[0..2]}-#{ssn[3..4]}-#{ssn[5..8]}"
  end
  if !has_ssn?(string) 
    return string
  else 
    return results.join(", ")
  end
end
 
puts "format_ssns finds and reformat any SSNs in the string"
puts format_ssns("234601422, 350.80.0744, 013-60-8762") == "234-60-1422, 350-80-0744, 013-60-8762"
 
puts "format_ssns does not alter a string without SSNs in it"
string = "please confirm your identity: 44211422"
puts format_ssns(string) == string