Method: ActiveSupport::NumberHelper#number_to_rounded

Defined in:
activesupport/lib/active_support/number_helper.rb

#number_to_rounded(number, options = {}) ⇒ Object

Formats a number with the specified level of :precision (e.g., 112.32 has a precision of 2 if :significant is false, and 5 if :significant is true). You can customize the format in the options hash.

Options

  • :locale - Sets the locale to be used for formatting (defaults to current locale).

  • :precision - Sets the precision of the number (defaults to 3).

  • :significant - If true, precision will be the # of significant_digits. If false, the # of fractional digits (defaults to false).

  • :separator - Sets the separator between the fractional and integer digits (defaults to “.”).

  • :delimiter - Sets the thousands delimiter (defaults to “”).

  • :strip_insignificant_zeros - If true removes insignificant zeros after the decimal separator (defaults to false).

Examples

number_to_rounded(111.2345)                                  # => 111.235
number_to_rounded(111.2345, precision: 2)                    # => 111.23
number_to_rounded(13, precision: 5)                          # => 13.00000
number_to_rounded(389.32314, precision: 0)                   # => 389
number_to_rounded(111.2345, significant: true)               # => 111
number_to_rounded(111.2345, precision: 1, significant: true) # => 100
number_to_rounded(13, precision: 5, significant: true)       # => 13.000
number_to_rounded(111.234, locale: :fr)                      # => 111,234

number_to_rounded(13, precision: 5, significant: true, strip_insignificant_zeros: true)
# => 13

number_to_rounded(389.32314, precision: 4, significant: true) # => 389.3
number_to_rounded(1111.2345, precision: 2, separator: ',', delimiter: '.')
# => 1.111,23


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# File 'activesupport/lib/active_support/number_helper.rb', line 342

def number_to_rounded(number, options = {})
  return number unless valid_float?(number)
  number  = Float(number)
  options = options.symbolize_keys

  defaults = format_options(options[:locale], :precision)
  options  = defaults.merge!(options)

  precision = options.delete :precision
  significant = options.delete :significant
  strip_insignificant_zeros = options.delete :strip_insignificant_zeros

  if significant && precision > 0
    if number == 0
      digits, rounded_number = 1, 0
    else
      digits = (Math.log10(number.abs) + 1).floor
      multiplier = 10 ** (digits - precision)
      rounded_number = (BigDecimal.new(number.to_s) / BigDecimal.new(multiplier.to_f.to_s)).round.to_f * multiplier
      digits = (Math.log10(rounded_number.abs) + 1).floor # After rounding, the number of digits may have changed
    end
    precision -= digits
    precision = 0 if precision < 0 # don't let it be negative
  else
    rounded_number = BigDecimal.new(number.to_s).round(precision).to_f
    rounded_number = rounded_number.abs if rounded_number.zero? # prevent showing negative zeros
  end
  formatted_number = self.number_to_delimited("%01.#{precision}f" % rounded_number, options)
  if strip_insignificant_zeros
    escaped_separator = Regexp.escape(options[:separator])
    formatted_number.sub(/(#{escaped_separator})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_separator}\z/, '')
  else
    formatted_number
  end
end