Using number_with_precision on controller in rails3

问题

I want to use this helper method on controller. Any way to achieve this?

回答1:

Probably not a great idea, but if you must, include the helper like so:

class WhateverController
  include ActionView::Helpers::NumberHelper

  def show
    render :text => number_with_precision(2342.234, :precision => 2)
  end

end

回答2:

A much better way to control number precision is rails controllers is to use sprintf

"%.2f" % 2342.234 => "2342.23"
"%.6f" % 2342.234 => "2342.234000"

来源：https://stackoverflow.com/questions/4426315/using-number-with-precision-on-controller-in-rails3