Localization

Localization

Translate strings and assets per language and use Text/NSLocalizedString to display localized content.

Localize Strings

Add Localizable.strings per language and use NSLocalizedString or SwiftUI's Text("key").

Syntax: "key" = "value"; in each Localizable.strings, read with NSLocalizedString("key", comment: "") or Text("key").

"hello" = "Hello";
"welcome_name" = "Welcome, %@";

"hello" = "Hola";
"welcome_name" = "Bienvenido, %@";

import SwiftUI

struct ContentView: View {
  var body: some View {
    VStack {
      Text("hello")
      Text(String(format: NSLocalizedString("welcome_name", comment: ""), "Swift"))
    }
  }
}

Pluralization (.stringsdict)

Use .stringsdict to support plural rules that vary by language.

{
  "apples_count" : {
    "NSStringLocalizedFormatKey" : "%#@apples@",
    "apples" : {
      "NSStringFormatSpecTypeKey" : "NSStringPluralRuleType",
      "NSStringFormatValueTypeKey" : "d",
      "one" : "%d apple",
      "other" : "%d apples"
    }
  }
}

import SwiftUI

struct CounterView: View {
  let count: Int
  var body: some View {
    Text(String.localizedStringWithFormat(NSLocalizedString("apples_count", comment: ""), count))
  }
}

SwiftUI Localization Tips

• Prefer Text("key") for static keys present in Localizable.strings.
• For values, compose with String.localizedStringWithFormat and a localized key (supports .stringsdict).
• Use system formatters for locale-aware output: numbers, dates, currency.

import SwiftUI

struct PricesView: View {
  let price: Double = 12.5
  let date = Date()
  var body: some View {
    VStack(alignment: .leading) {
      Text(price, format: .currency(code: Locale.current.currency?.identifier ?? "USD"))
      Text(date, style: .date)
    }
  }
}

Testing Localization

• In Xcode scheme, set Application Language to a target language or a Pseudolanguage to catch truncation.
• Test Right-to-Left using the Right-to-Left Pseudolanguage and verify UI flips correctly.
• Avoid hard-coded strings; every user-facing string should be a key in Localizable.strings.
• Use String Catalogs in modern Xcode to manage keys and translations at scale.

App Metadata

Localize your App Store listing: name, subtitle, description, and screenshots per locale.