This brief post will show you how to validate currency in your Ruby on Rails app.

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Published on:October 10, 2013

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If you ever need to validate currency in your Ruby on Rails app, simply add the following line of code to the model of your choice.

validates :price, :presence => true,
            :numericality => true,
            :format => { :with => /^\d{1,4}(\.\d{0,2})?$/ }

This will allow values of up to $9999.99 with an optional decimal place (if the decimal is present, no more than 2 digits must follow.) Tweak as needed.