篩選兩個陣列夫特

Question

我有一個空數組和兩個陣列與數據

var resultsArray = [String]() 

var array1 = ["1","2","2","3","4"] 
var array2 = ["1","2","2","3","4","5","6"] 

我的目標是在resultsArray與元件追加從array2不匹配array1（「5」和「6」在這個例子中）。

這樣做最微妙的方法是什麼？

謝謝。

Answer 1

使用filter功能

var resultsArray = [String]() 

let array1 = ["1","2","2","3","4"] 
let array2 = ["1","2","2","3","4","5","6"] 

let filteredArray = array2.filter{ !array1.contains($0) } 

resultsArray.appendContentsOf(filteredArray) 

如果集合包含了獨特的項目考慮使用Set，而不是Array

Answer 2

使用過濾功能爲目的，以發現不同數量的元素的兩個數組

在

let Filter = array2.filter{!array1} 
resultArray.appendContentsof(Filter) 

Answer 3

var resultsArray: [String] = [] 

let arrayX = ["1","2","2","3","4"] 
let arrayY = ["1","2","2","3","4","5","6","7"] 

let setX = Set(arrayX), setY = Set(arrayY) 

resultsArray.append(contentsOf: setY.subtracting(setX)) 

這個答案比使用過濾器快。