Store value from regex to variable in Ruby

Question

I have a method in a model with Rails. This is the code:

def ensure_appropriate_age
  age = match[:age]

  if age[/\d/].to_i > 18
    current_user.update age: age[/\d/].to_i
  else
    %{We could not proceed, sorry.}
  end
end

I'm taking the input of what the user types and if it contains a number, verify that it is greater than 18 to store it.

I'll enter my age like so: im 24. I still get false, and I can see in the database it's only storing the number "2".

What is required to make this work?

Michael Gaskill · Accepted Answer · 2016-05-27 21:55:44Z

4

You have to use \d+ to match multiple digits; \d only matches a single digit in a number.

You can also capture the value of the regex into a variable, so that you don't have to evaluate it twice, like shown:

def ensure_appropriate_age(age_string)
  age = age_string[/\d+/].to_i

  if age > 18
    current_user.update age: age
  else
    %{We could not proceed, sorry.}
  end
end

answered May 27, 2016 at 21:55

Michael Gaskill

8,06210 gold badges40 silver badges46 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Giuse · Accepted Answer · 2016-05-28 13:46:52Z

It's good to step back a second, and ask yourself why do you need to extract the age from a string here. What else are you holding in it? If more information is present, build a quick parser in the caller or initializer to partition the data, and cast to the proper types.

The trick is: once the age is isolated from the other information, casting is straightforward.

user_data = "John Smith 22"
@name, @surname, age_str = user_data.split(" ")
@age = age_str.to_i

Then just use your function. Ruby style guides also advise you to use quotes "..."rather than
%{} unless needed (i.e. your string is full of quotes).

If you push yourself to keep it simple whenever you can, you will find your code easier to read and faster to write and debug. There's plenty cases in which regex(es?) are the simplest way to go, but until you get there don't sweat it :)

Collectives™ on Stack Overflow

Store value from regex to variable in Ruby

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related