Swift开发中应使用Array还是NSArray？

Hey there! You’ve already nailed the key difference between these two: Array is Swift’s native value type (a struct), while NSArray is an Objective-C reference type (a class). Let’s walk through the scenarios where each is the right call:

Stick with Array (Swift’s Native Collection) #

• Your default for Swift code: This should be your go-to 90% of the time. As a value type, it uses copy-on-write—so when you pass it around, you won’t get unexpected changes from other parts of your code messing with the same array under the hood. It integrates seamlessly with Swift’s generics, type safety, and all those handy higher-order functions like map, filter, and reduce.
• Working with modern Swift frameworks: If you’re using SwiftUI, Combine, or any of Apple’s newer Swift-first tools, Array is the standard collection type you’ll be working with.
• Performance-focused work: Swift’s optimizations for value types mean Array often runs smoother in pure Swift contexts, especially with smaller to medium-sized datasets.

Reach for NSArray When… #

• You’re interfacing with Objective-C: If you’re working with legacy Objective-C codebases, APIs that only accept NSArray, or need to bridge between Swift and Objective-C, you’ll need to use NSArray (or bridge your Swift Array to it with as NSArray).
• You need reference-type behavior: Since NSArray is a class, passing it around shares a reference to the same underlying array. If you intentionally want multiple parts of your code to modify the exact same collection instance (just be careful with unintended side effects!), this is a use case for NSArray.
• You need Objective-C-specific methods: Some older collection utilities only exist on NSArray (like componentsJoinedByString:—though Swift’s joined(separator:) is the modern replacement). If compatibility requires using these, you’ll have to work with NSArray.

One quick tip: Converting between the two is straightforward when you need to—let swiftArray = nsArray as? [String] or let nsArray = swiftArray as NSArray—so you can switch between them without much hassle.

内容的提问来源于stack exchange，提问作者whitekevin