When dealing with localized strings in Swift, especially for UI elements, choosing the right approach is crucial. Here’s a breakdown of the options:

1️⃣ LocalizedStringKey (Best for SwiftUI)

• Use when: You are directly using a string in a SwiftUI view (e.g., Text("hello_world")).

• Why? SwiftUI automatically localizes LocalizedStringKey, making it the best choice for UI text.

• Example:

  Text("hello_world") // Automatically looks for "hello_world" in Localizable.strings 
  

• Pros:
  ✅ No need to manually use NSLocalizedString
  ✅ Cleaner SwiftUI code
  ✅ Supports string interpolation

• Cons:
  ❌ Can’t be used outside SwiftUI (e.g., in business logic)

2️⃣ LocalizedStringResource (Best for Performance)

• Use when: You need efficient string translation with better memory handling.

• Introduced in: iOS 16

• Why? It is more optimized than LocalizedStringKey, but still works well with SwiftUI.

• Example:

  Text(LocalizedStringResource("hello_world")) 
  

• Pros:
  ✅ More optimized for localization
  ✅ Reduces memory overhead

• Cons:
  ❌ Requires iOS 16+

3️⃣ String with NSLocalizedString (Best for Non-SwiftUI Code)

• Use when: You are not using SwiftUI, but need translations in ViewModels, controllers, or business logic.

• Why? NSLocalizedString fetches translations from Localizable.strings.

• Example:

  let greeting = NSLocalizedString("hello_world", comment: "Greeting message") print(greeting)
  

• Pros:
  ✅ Works anywhere (UIKit, business logic, networking)
  ✅ Supports dynamic strings

• Cons:
  ❌ Not automatically localized in SwiftUI
  ❌ More verbose