Dictionary comparison

DictionaryComparison.swift

import Foundation

let dictOne: [String: String] = [
    "key1": "value one",
    "key2": "value two",
    "key3": "value three",
    "key4": "value four"
]

let dictTwo: [String: String] = [
    "key1": "value one",
    "key3": "value 3",
    "key4": "value four",
    "key5": "value five"
]

let addedKeys = Array(Set(dictTwo.keys).subtracting(Set(dictOne.keys)))
let removedKeys = Array(Set(dictOne.keys).subtracting(Set(dictTwo.keys)))
let remainingKey = Array(Set(dictTwo.keys).subtracting(Set(removedKeys)).subtracting(Set(addedKeys)))
let changedKeys = remainingKey.compactMap { (dictOne[$0] != dictTwo[$0]) ? $0 : nil }

debugPrint("Added keys: \(addedKeys)") // "Added keys: [\"key5\"]"
debugPrint("Removed keys: \(removedKeys)") // "Removed keys: [\"key2\"]"
debugPrint("Remaining keys: \(remainingKey)") // "Remaining keys: [\"key1\", \"key4\", \"key3\"]"
debugPrint("Changed keys: \(changedKeys)") // "Changed keys: [\"key3\"]"