How to implement an object in Ruby with regex - ruby-on-rails

Question

Absolute beginner in Ruby.
I need to create a class that contains the following keys:
I know that this might be the structure, but can anybody help me with syntax?
class PixKey
def cpf
^[0-9]{11}$
end
def cnpj
^[0-9]{14}$
end
def phone
^\+[1-9][0-9]\d{1,14}$
end
def email
^[a-z0-9.!#$&'*+\/=?^_`{
end
def evp
[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}
end
end

Answer 1

You can define regular expressions using the /.../ regular expression literal.
Since regular expressions are immutable, I would simply use constants:
class PixKey
CPF = /^[0-9]{11}$/
CNPJ = /^[0-9]{14}$/
PHONE = /^\+[1-9][0-9]\d{1,14}$/
EMAIL = /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+#[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/
EVP = /[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/
end
In the above, I've changed the email regexp to the one suggested by the HTML standard because the one in your screenshot was probably destroyed by a markdown parser.
You can use the above like this:
PixKey::CPF.match?('12345678901') #=> true
PixKey::CNPJ.match?('12345678901234') #=> true
PixKey::PHONE.match?('[phone]') #=> true
PixKey::EMAIL.match?('pix#bcb.gov.br') #=> true
PixKey::EVP.match?('123e4567-e89b-12d3-a456-426655440000') #=> true
Of course, you're not limited to match?, you can use any method from the Regexp class or pattern matching methods from String.
Note that in Ruby, ^ and $ match beginning and end of line which can cause problems in multi-line strings:
string = "before
[phone]
after"
string.match?(PixKey::PHONE) #=> true
If you want to match beginning and end of string (i.e. only match whole strings), you can use \A and \z instead:
PixKey::PHONE = /\A\+[1-9][0-9]\d{1,14}\z/
string = "before
[phone]
after"
string.match?(PixKey::PHONE) #=> false
string = '[phone]'
string.match?(PixKey::PHONE) #=> true

Answer 2

To return the regular expressions for further use, you could return the regex using /:
class PixKey
def cpf
/^[0-9]{11}$/
end
end
You could run PixKey.new.cpf to return the regex:
irb(main):022:0> PixKey.new.cpf
=> /^[0-9]{11}$/
You could also make it a class method by putting self. in front of the method name or add the line class << self as the first line in your class to make them all class methods by default (don't forget the end in this case).
class PixKey
def self.cpf
/^[0-9]{11}$/
end
end
class PixKey
class << self
def cpf
/^[0-9]{11}$/
end
end
end
With this you could run PixKey.cpf to return the regex:
irb(main):022:0> PixKey.cpf
=> /^[0-9]{11}$/