Localized String Properties

Each key-value pair in the .stringsdict file defines a plural rule for a specific string, as in:

<plist version="1.0">

    <dict>

        <key>%d file(s) remaining</key>

        <dict>

            …

        </dict>

        <key>%d service hour(s)</key>

        <dict>

            …

        </dict>

        <key>%d award(s)</key>

        <dict>

            …

        </dict>

    </dict>

</plist>

You pass the same strings—for example, @”%d file(s) remaining”, @”%d service hour(s)” and @”%d award(s)”—to a NSLocalizedString macro in your code.

Localized Format String Properties

The plural rule determines the format string returned by the NSLocalizedString macro. You supply a format string for each category of numbers the language defines. The value of this dictionary has the following keys:

NSStringLocalizedFormatKey

A format string that contains variables. A variable is preceded by the %#@ characters and followed by the @ character, as in:

<key>NSStringLocalizedFormatKey</key>

<string>%#@files@</string>

where the variable name is files. The format string can contain multiple variables, as in %#@files@ (%#@bytes@, %#@minutes@).

[variable]

A dictionary of key-value pairs specifying the rule to use for [variable], as in:

<key>files</key>

<dict>

<key>NSStringFormatSpecTypeKey</key>

<string>NSStringPluralRuleType</string>

<key>NSStringFormatValueTypeKey</key>

<string>d</string>

<key>one</key>

<string>%d file remaining</string>

<key>other</key>

<string>%d files remaining</string>

</dict>

For example, if the number is 2, the @”%d files remaining” format string is returned and the localized string becomes @”2 files remaining”.

Add plural rules for each variable that appears in the NSStringLocalizedFormatKey format string.

Plural Rule Properties

The [variable] dictionary contains the following keys:

NSStringFormatSpecTypeKey

Specifies the type of language rule. The only possible value is NSStringPluralRuleType, which indicates a language plural rule.

NSStringFormatValueTypeKey

A string format specifier for a number, as in %d for an integer. For a list of format specifiers, see String Format Specifiers in String Programming Guide.

zero

The format string to use for the number 0.

one

The format string to use for additional language-dependent categories.

two

The format string to use for additional language-dependent categories.

few, many

Format strings to use for additional language-dependent categories.

other

The format string to use for all numbers not covered by the other categories. This key is required.

• The meaning of the categories is language-dependent, and not all languages have the same categories.

  For example, English only uses the one and other categories to represent plural forms. Arabic has different plural forms for the zero, one, two, few, many, and other categories. Although Russian also uses the many category, the rules for which numbers are in the many category are not the same as the Arabic rules.

• All of the categories are optional except other.

  However, your text may be grammatically incorrect if you don’t supply a rule for all the language-specific categories. Conversely, if you provide a rule for a category not used by a language, it is ignored and the other format string is used.

• Using the NSStringFormatValueTypeKey format specifier in the zero, one, two, few, many, and other format strings is optional.

  For example, the one format string can be One file remaining while the other format string can be %d files remaining for English.

• Use the format specifier or spell out numbers in the format strings.

  If you use a numeric in the format string, as in 1 file remaining for English, it may not be localized when the user changes the region (for example, if the number set changes). Instead, use the format specifier, as in %d file remaining; otherwise, spell out the number, as in One file remaining.

For the plural categories and rules for each language, see CLDR Language Plural Rules.