展平[Any]数组迅捷 [英] Flatten [Any] Array Swift

问题描述

使用此堆栈溢出问题我有以下代码.

let numbers = [1,[2,3]] as [Any]
var flattened = numbers.flatMap { $0 }
print(flattened) // [1, [2, 3]]

我希望将其设置为[1, 2, 3]，而不是将其展平.

在Swift中最简单/最干净的方法是什么?

解决方案

extension Collection {
    func joined() -> [Any] {
        return flatMap { ($0 as? [Any])?.joined() ?? [$0] }
    }
    func flatMapped<T>(with type: T.Type? = nil) -> [T] {
        return joined().compactMap { $0 as? T }
    }
}

---

let objects: [Any] = [1,[2,3],"a",["b",["c","d"]]]
let joined = objects.joined()   // [1, 2, 3, "a", "b", "c", "d"]

let integers = objects.flatMapped(with: Int.self)  // [1, 2, 3]
// setting the type explicitly
let integers2: [Int] = objects.flatMapped()        // [1, 2, 3]
// or casting
let strings = objects.flatMapped() as [String]     // ["a", "b", "c", "d"]

Using this Stack Overflow question I have the following code.

let numbers = [1,[2,3]] as [Any]
var flattened = numbers.flatMap { $0 }
print(flattened) // [1, [2, 3]]

Instead of flattened being set to [1, [2, 3]] I want it to be [1, 2, 3].

What is the easiest/cleanest way to achieve this in Swift?

解决方案

extension Collection {
    func joined() -> [Any] {
        return flatMap { ($0 as? [Any])?.joined() ?? [$0] }
    }
    func flatMapped<T>(with type: T.Type? = nil) -> [T] {
        return joined().compactMap { $0 as? T }
    }
}

---

let objects: [Any] = [1,[2,3],"a",["b",["c","d"]]]
let joined = objects.joined()   // [1, 2, 3, "a", "b", "c", "d"]

let integers = objects.flatMapped(with: Int.self)  // [1, 2, 3]
// setting the type explicitly
let integers2: [Int] = objects.flatMapped()        // [1, 2, 3]
// or casting
let strings = objects.flatMapped() as [String]     // ["a", "b", "c", "d"]

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