Which of the following are valid objects of class Integer or one of its subclasses? 1) -123 2) 0xFF 3) 123_456_789 4) 123456789123456789123456789123456789

What's an equivalent way of performing the following (h is a Hash): h.each { |k,v| h.delete k if k.nil? }

In The Author Model, how do you create a nested association between Authors and Blogs?

Which is not a valid callback?

Determine the value of the variable a, b and c after the execution of the following code. a, b, c = 1, 2, 3, 4

In development mode (config.assets.digest = false), if a file exists in app/assets/javascript/hello.js, which link will show that file ?

Which of the following protects 'NOT NULL' fields against missing a user input?

Which is not an advantage of using an integrated development environment (IDE) for Rails ,compared with using a simple text editor?

How can the Heroku deprecation warning be removed from a Rails plugin that has been used?

What is TDD is rails3?

Which of these tools are for checking Ruby code styling?