Question

我有两个数组

var array1 = new Array ["a", "b", "c", "d", "e"]
var array2 = new Array ["a", "c", "d"]

我想从array1中删除array2的元素

Result ["b", "e"]

Answer 1

@ Antonio's solution性能更高，但如果这很重要，这会保留排序：

var array1 = ["a", "b", "c", "d", "e"]
let array2 = ["a", "c", "d"]
array1 = array1.filter { !array2.contains($0) }

Answer 2

最简单的方法是将两个数组转换为集合，从第一个数组中减去第二个数组，将结果转换为数组并将其分配回array1：

array1 = Array(Set(array1).subtracting(array2))

请注意，您的代码无效Swift - 您可以使用类型推断来声明和初始化两个数组，如下所示：

var array1 = ["a", "b", "c", "d", "e"]
var array2 = ["a", "c", "d"]

Answer 3

使用索引数组删除元素：

字符串和索引数组

let animals = ["cats", "dogs", "chimps", "moose", "squarrel", "cow"]
let indexAnimals = [0, 3, 4]
let arrayRemainingAnimals = animals
    .enumerated()
    .filter { !indexAnimals.contains($0.offset) }
    .map { $0.element }

print(arrayRemainingAnimals)

//result - ["dogs", "chimps", "cow"]

整数和索引数组

var numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
let indexesToRemove = [3, 5, 8, 12]

numbers = numbers
    .enumerated()
    .filter { !indexesToRemove.contains($0.offset) }
    .map { $0.element }

print(numbers)

//result - [0, 1, 2, 4, 6, 7, 9, 10, 11]

使用其他数组的元素值删除元素

整数数组

let arrayResult = numbers.filter { element in
    return !indexesToRemove.contains(element)
}
print(arrayResult)

//result - [0, 1, 2, 4, 6, 7, 9, 10, 11]

字符串数组

let arrayLetters = ["a", "b", "c", "d", "e", "f", "g", "h", "i"]
let arrayRemoveLetters = ["a", "e", "g", "h"]
let arrayRemainingLetters = arrayLetters.filter {
    !arrayRemoveLetters.contains($0)
}

print(arrayRemainingLetters)

//result - ["b", "c", "d", "f", "i"]

Answer 4

您可以创建集合，然后使用减法方法

let setA = Set(arr1)
let setB = Set(arr2)
setA.subtract(set2)

Answer 5

超出范围但如果它在这里它会帮助我。从 OBJECTIVE-C

中的数组中删除subArray

NSPredicate* predicate = [NSPredicate predicateWithFormat:@"not (self IN %@)", subArrayToBeDeleted];
NSArray* finalArray = [initialArray filteredArrayUsingPredicate:predicate];

希望它能帮助别人:)

Answer 6

Shai Balassiano 答案的扩展版本：

extension Array where Element: Equatable {
  func subtracting(_ array: [Element]) -> [Element] {
      self.filter { !array.contains($0) }
  }

  mutating func remove(_ array: [Element]) {
      self = self.subtracting(array)
  }
}

Answer 7

以下是@jrc答案的扩展名：

extension Array where Element: Equatable {
    func subtracting(_ array: Array<Element>) -> Array<Element> {
        self.filter { !array.contains($0) }
    }
}

iOS swift从另一个数组中删除数组的元素

7 个答案: