Provides methods for converting a numbers into formatted strings. Methods are provided for phone numbers, currency, percentage, precision, positional notation, and file size.

Methods
Public Instance methods
human_size(size, precision=1)
number_to_currency(number, options = {})

Formats a number into a currency string. You can customize the format in the options hash.

  • :precision - Sets the level of precision, defaults to 2
  • :unit - Sets the denomination of the currency, defaults to "$"
  • :separator - Sets the separator between the units, defaults to "."
  • :delimiter - Sets the thousands delimiter, defaults to ","
 number_to_currency(1234567890.50)     => $1,234,567,890.50
 number_to_currency(1234567890.506)    => $1,234,567,890.51
 number_to_currency(1234567890.506, :precision => 3)    => $1,234,567,890.506
 number_to_currency(1234567890.50, :unit => "£", :separator => ",", :delimiter => "")
    => £1234567890,50
    # File vendor/rails/actionpack/lib/action_view/helpers/number_helper.rb, line 55
55:       def number_to_currency(number, options = {})
56:         options   = options.stringify_keys
57:         precision = options["precision"] || 2
58:         unit      = options["unit"] || "$"
59:         separator = precision > 0 ? options["separator"] || "." : ""
60:         delimiter = options["delimiter"] || ","
61:         
62:         begin
63:           parts = number_with_precision(number, precision).split('.')
64:           unit + number_with_delimiter(parts[0], delimiter) + separator + parts[1].to_s
65:         rescue
66:           number
67:         end
68:       end
number_to_human_size(size, precision=1)

Formats the bytes in size into a more understandable representation. Useful for reporting file sizes to users. This method returns nil if size cannot be converted into a number. You can change the default precision of 1 in precision.

 number_to_human_size(123)           => 123 Bytes
 number_to_human_size(1234)          => 1.2 KB
 number_to_human_size(12345)         => 12.1 KB
 number_to_human_size(1234567)       => 1.2 MB
 number_to_human_size(1234567890)    => 1.1 GB
 number_to_human_size(1234567890123) => 1.1 TB
 number_to_human_size(1234567, 2)    => 1.18 MB
This method is also aliased as human_size
     # File vendor/rails/actionpack/lib/action_view/helpers/number_helper.rb, line 137
137:       def number_to_human_size(size, precision=1)
138:         size = Kernel.Float(size)
139:         case 
140:           when size == 1        : "1 Byte"
141:           when size < 1.kilobyte: "%d Bytes" % size
142:           when size < 1.megabyte: "%.#{precision}f KB"  % (size / 1.0.kilobyte)
143:           when size < 1.gigabyte: "%.#{precision}f MB"  % (size / 1.0.megabyte)
144:           when size < 1.terabyte: "%.#{precision}f GB"  % (size / 1.0.gigabyte)
145:           else                    "%.#{precision}f TB"  % (size / 1.0.terabyte)
146:         end.sub('.0', '')
147:       rescue
148:         nil
149:       end
number_to_percentage(number, options = {})

Formats a number as a percentage string. You can customize the format in the options hash.

  • :precision - Sets the level of precision, defaults to 3
  • :separator - Sets the separator between the units, defaults to "."
 number_to_percentage(100)    => 100.000%
 number_to_percentage(100, {:precision => 0})   => 100%
 number_to_percentage(302.0574, {:precision => 2})   => 302.06%
    # File vendor/rails/actionpack/lib/action_view/helpers/number_helper.rb, line 78
78:       def number_to_percentage(number, options = {})
79:         options   = options.stringify_keys
80:         precision = options["precision"] || 3
81:         separator = options["separator"] || "."
82:         
83:         begin
84:           number = number_with_precision(number, precision)
85:           parts = number.split('.')
86:           if parts.at(1).nil?
87:             parts[0] + "%"
88:           else
89:             parts[0] + separator + parts[1].to_s + "%"
90:           end
91:         rescue
92:           number
93:         end
94:       end
number_to_phone(number, options = {})

Formats a number into a US phone number. You can customize the format in the options hash.

  • :area_code - Adds parentheses around the area code.
  • :delimiter - Specifies the delimiter to use, defaults to "-".
  • :extension - Specifies an extension to add to the end of the generated number
  • :country_code - Sets the country code for the phone number.
 number_to_phone(1235551234)   => 123-555-1234
 number_to_phone(1235551234, :area_code => true)   => (123) 555-1234
 number_to_phone(1235551234, :delimiter => " ")    => 123 555 1234
 number_to_phone(1235551234, :area_code => true, :extension => 555)  => (123) 555-1234 x 555
 number_to_phone(1235551234, :country_code => 1)
    # File vendor/rails/actionpack/lib/action_view/helpers/number_helper.rb, line 20
20:       def number_to_phone(number, options = {})
21:         number       = number.to_s.strip unless number.nil?
22:         options      = options.stringify_keys
23:         area_code    = options["area_code"] || nil
24:         delimiter    = options["delimiter"] || "-"
25:         extension    = options["extension"].to_s.strip || nil
26:         country_code = options["country_code"] || nil
27: 
28:         begin
29:           str = ""
30:           str << "+#{country_code}#{delimiter}" unless country_code.blank?
31:           str << if area_code
32:             number.gsub!(/([0-9]{1,3})([0-9]{3})([0-9]{4}$)/,"(\\1) \\2#{delimiter}\\3")
33:           else
34:             number.gsub!(/([0-9]{1,3})([0-9]{3})([0-9]{4})$/,"\\1#{delimiter}\\2#{delimiter}\\3")
35:           end
36:           str << " x #{extension}" unless extension.blank?
37:           str
38:         rescue
39:           number
40:         end
41:       end
number_with_delimiter(number, delimiter=",", separator=".")

Formats a number with grouped thousands using delimiter. You can customize the format in the options hash.

  • :delimiter - Sets the thousands delimiter, defaults to ","
  • :separator - Sets the separator between the units, defaults to "."
 number_with_delimiter(12345678)      => 12,345,678
 number_with_delimiter(12345678.05)   => 12,345,678.05
 number_with_delimiter(12345678, :delimiter => ".")   => 12.345.678
     # File vendor/rails/actionpack/lib/action_view/helpers/number_helper.rb, line 104
104:       def number_with_delimiter(number, delimiter=",", separator=".")
105:         begin
106:           parts = number.to_s.split(separator)
107:           parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{delimiter}")
108:           parts.join separator
109:         rescue
110:           number
111:         end
112:       end
number_with_precision(number, precision=3)

Formats a number with the specified level of precision. The default level of precision is 3.

 number_with_precision(111.2345)    => 111.235
 number_with_precision(111.2345, 2) => 111.24
     # File vendor/rails/actionpack/lib/action_view/helpers/number_helper.rb, line 119
119:       def number_with_precision(number, precision=3)
120:         "%01.#{precision}f" % number
121:       rescue
122:         number
123:       end