Swift：获取由某个属性筛选的对象数组的索引

Question

我有一个自定义对象数组，将ID值作为属性。现在我有了另一个选定对象数组（由IDs选定）。如何通过筛选选定的ID（第二个数组）来获得第一个数组的索引？

我希望避免循环，并考虑使用CompactMap或类似的解决方案。

struct MyObject {
    var ID: Int
    var name: String
}

let myObjects = [
    MyObject(ID: 3, name: "AAAA"),
    MyObject(ID: 5, name: "BBBB"),
    MyObject(ID: 12, name: "CCCC"),
    MyObject(ID: 15, name: "DDDD"),
    MyObject(ID: 20, name: "EEEE"),
    MyObject(ID: 21, name: "GGGG"),
    MyObject(ID: 22, name: "HHHH"),
    MyObject(ID: 23, name: "IIII"),
]
let selectedIds = [5, 20, 23]

// How to get an array of indices for selectedIds
// Expected result [1, 4, 7]

Answer 1

myObjects.enumerated()   // Pair-up elements and their offsets
    .filter { selectedIds.contains($0.element.ID) }  // Get the ones you want
    .map { $0.offset }  // Extract the offsets