如何在数组上映射方法？

Question

Let's say I have a method (which is actually a helper):

def f(x)  
  x + 1  
end

What I want to do is to map it over an enumerable like so:

(1..10).map &f

It's obviously doesn't work raising ArgumentError: wrong number of arguments (0 for 1) error. I know that I can call this method in block like so:

(1..10).map {|x| f x }

But it doesn't look like an elegant solution to me. What else can be done about it?

Answer 1

您可以使用：

(1..10).map(&method(:f))

Answer 2

First of all, I don't see any inelegance in this

(1..10).map {|x| f x }

Normally, you should be using it. But, under special circumstances, a special form is available (you need to call a method on an object and that method doesn't accept arguments).

class Fixnum
  def f
    self + 1
  end
end

(1..10).map(&:f)

Between these two approaches, I'd take the first one any day.