&:

The ampersand-colon combo turns out to be quite useful in saving keystrokes. What I had been doing was creating a new array of numbers. To do so quickly, I needed to use %w, which makes an array of strings.

ary = %w(23 45 68 120 345 760 1220)

The old way I converted to a number was the following:

ary.map! { |x| x.to_i }

(Naturally, I prefer map over collect, which does the same thing, not just because of the keystroke, but because I used Scheme before.) I discovered a shorter way:

ary.map!(&:to_i)

Actually, instead of doing it separately, why not combine the whole thing?

ary = %w(23 45 68 120 345 760 1220).map(&:to_i)

It saves using exclamation point and feels less dangerous.

class Person
  def initialize(name)
    @name = name
  end

  def name
    return @name
  end
end

class Doctor < Person
  def name
    “Dr. “ + super
  end
end

That, in short, is how super works. Taken from Beginning Ruby by Peter Cooper.

super

in short calls up the parent class’ instance method.

Like most endings, I do not feel the tragedy because the shuttle program was born before my time. It felt like a common occurrence to have something flying off into space–perhaps I lost the capacity for awe.

via Bacteria ‘R’ Us