Swift・SwiftUI・Combine・ObservableObject チャレンジ このコード例の場合、「object1 will change」・「object2 will change」・「object3 will change」はそれぞれそれぞれ何回 print されるか？

ObservableObjectPlaygrounds.swift

import Combine
import Foundation

// MARK: - パターン1

final class Object1: ObservableObject {
    @Published var value1 = 0
    @Published var value2 = 0
    @Published var value3 = 0
}

// MARK: - パターン2

struct Properties2 {
    var value1 = 0
    var value2 = 0
    var value3 = 0
}

final class Object2: ObservableObject {
    @Published var properties = Properties2()
}

// MARK: - パターン3

struct Properties3 {
    let value1: Int
    let value2: Int
    let value3: Int
}

final class Object3: ObservableObject {
    @Published var properties = Properties3(value1: 0, value2: 0, value3: 0)
}

// MARK: - 実行

let object1 = Object1()
let object2 = Object2()
let object3 = Object3()

let cancellable1 = object1.objectWillChange
    .sink { _ in
        print("object1 will change")
    }

let cancellable2 = object2.objectWillChange
    .sink { _ in
        print("object2 will change")
    }

let cancellable3 = object3.objectWillChange
    .sink { _ in
        print("object3 will change")
    }


object1.value1 = 1
object1.value2 = 2
object1.value3 = 3

object2.properties.value1 = 1
object2.properties.value2 = 2
object2.properties.value3 = 3

object3.properties = .init(value1: 1, value2: 2, value3: 3)

// Q. "object1 will change"・"object2 will change"・"object3 will change" は
//    それぞれ何回 print されるか？

RunLoop.current.run()

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