Localizing Numbers in iPhone Apps: A Practical Guide
Understanding the Challenges
When building an iPhone app, you often need to display object counts, such as the number of items in a collection or the count of errors in a log file. While English makes it easy to distinguish between singular and plural forms using a simple rule (adding an ’s’ to form the plural), other languages have more complex rules for constructing plural forms. This can lead to challenges when localizing your app’s text.
In this article, we’ll explore the complexities of localizing numbers in iPhone apps and provide practical guidance on how to handle these challenges.
The Problem with English
English is a Germanic language that follows relatively simple rules for forming plurals. In most cases, you can add an ’s’ to form the plural of a noun (e.g., “cat” becomes “cats”). However, even in English, there are exceptions and irregularities, such as:
- Irregular plural forms like “child” (one child) vs. “children” (more than one child)
- Plural forms that don’t follow the usual ’s’ pattern, like “tooth” (one tooth) vs. “teeth” (more than one tooth)
The Challenges of Localizing Numbers
When localizing your app for other languages, you’ll encounter similar complexities and irregularities. While some languages may have relatively simple plural forms, others may require more nuanced handling.
There are two main challenges to consider:
- Forming plural nouns: Different languages have unique rules for constructing plural forms, which can be difficult to support programmatically.
- Number of plural forms: Some languages have multiple plural forms (e.g., masculine and feminine) or irregularities that make it harder to determine the correct plural form.
Using NSLocalizedString for Localization
In your iPhone app, you’re already using NSLocalizedString to localize text. This function reads from a string table in your app bundle, which means you can only support languages at compile time.
While it’s tempting to try to handle every possible language and plural form, this approach can become unwieldy and prone to errors. Instead, focus on supporting the languages you’re specifically targeting for your app.
Solution: Supporting Specific Languages
To localize numbers in your iPhone app, follow these steps:
- Identify the target languages: Determine which languages you need to support for your app.
- Create a string table: Create separate Localizable.strings files for each supported language (e.g., en.lproj/Localizable.strings).
- Define plural forms: Define the plural forms for each noun or concept in your app, using the specific rules of the target languages.
Here’s an example of how you might define plural forms for a few English nouns:
// en.lproj/Localizable.strings
ObjectCount1 = "1 object"
ObjectCountEven = "%d objects"
ObjectCountOdd = "%d objects" // same as ObjectCountEven
And here’s an example of how you might define plural forms for the noun “object” in French:
// fr.lproj/Localizable.strings
ObjectCount1 = "1 objet"
ObjectCountEven = "%d objets"
ObjectCountOdd = "%d objet"
Handling Irregular Plural Forms
When dealing with irregular plural forms, you may need to use a more nuanced approach:
- Use custom code: Instead of relying on
NSLocalizedString, create custom code to handle irregular plural forms. This might involve using regular expressions or manual string manipulation. - Work with translators: Collaborate with your translators to identify and document any irregularities in the target language’s plural forms.
For example, if you’re working with a translator who requires separate strings for even and odd numbers in Martian, you can adjust your code as follows:
// Martian Localizable.strings
ObjectCount1 = "1 object-o"
ObjectCountEven = "%d object-e"
ObjectCountOdd = "%d object-o" // same as ObjectCount1
Conclusion
Localizing numbers in iPhone apps requires a nuanced approach to handle the complexities of different languages and plural forms. By supporting specific languages, creating custom string tables, and defining plural forms according to the rules of each target language, you can provide a seamless user experience for your app’s global audience.
Remember that human languages are messy and irregular, so it’s essential to prioritize clarity, consistency, and collaboration with translators when localizing your app.
Last modified on 2024-05-19