Regular Expression

regular_expression.rb

# # Determine whether a string contains a Social Security number.
def has_ssn?(string)
  /\d{3}-\d{2}-\d{4}/.match(string)
end

# Return the Social Security number from a string.
def grab_ssn(string)
  string[/\d{3}-\d{2}-\d{4}/]
end

# Return all of the Social Security numbers from a string.
def grab_all_ssns(string)
  ssn_array = []
  has_ssn?(string) ? string.split(",").each {|e| ssn_array << grab_ssn(e)} :  ssn_array
  ssn_array
end

# Obfuscate all of the Social Security numbers in a string. Example: XXX-XX-4430.
def hide_all_ssns(string)
    has_ssn?(string) ? grab_all_ssns(string).join(", ").gsub(/\d{3}-\d{2}/, 'XXX-XX') : string
end

# 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)
  digits = remove_special_chars(string)
  is_9digits?(digits) ? beautiful_ssn(digits) : string
end


def remove_special_chars(string)
  string.gsub(/[^\w\s]/, "")
end

def is_9digits?(input)
  /\d{9}/.match(input) ? (return true) : (return false)
end

def beautiful_ssn(crappy_ssn)
  crappy_ssn.gsub(/\d{5}/) {|s| s[0..2]+'-'+s[3..4]+'-'}.split(" ").join(", ")
end

Hey,

I don't think that you need to use that complicated algorithm to fetch all SSNs in grab_all_ssns().
Apparently Ruby are not supporting global pattern matching via /g :(

So I suppose you can do something like this:

# Return all of the Social Security numbers from a string.
def grab_all_ssns(string)
    string.scan(/\d{3}-\d{2}-\d{4}/)
end

In javascript it will look like this:

// Return all of the Social Security numbers from a string.
function grab_all_ssns(string) {
    return string.match(/\d{3}-\d{2}-\d{4}/g) || [];
}

P.S. I suppose that format_ssns() should be called before hide_all_ssns(), right?