是否有任何简单的方法可以在swift中合并两个数组并删除重复项？

Question

基本上我需要一个版本appendContentsOf:不附加重复元素.

例

var a = [1, 2, 3]
let b = [3, 4, 5]

a.mergeElements(b)
//gives a = [1, 2, 3, 4, 5] //order does not matter

Answer 1

简单地说

let unique = Array(Set(a + b))

Answer 2

Swift 5 更新

如果您需要组合多个数组。

func combine<T>(_ arrays: Array<T>?...) -> Set<T> {
    return arrays.compactMap{$0}.compactMap{Set($0)}.reduce(Set<T>()){$0.union($1)}
}

用法示例：

1.

    let stringArray1 = ["blue", "red", "green"]
    let stringArray2 = ["white", "blue", "black"]
    
    let combinedStringSet = combine(stringArray1, stringArray2)

    // Result: {"green", "blue", "red", "black", "white"}

    let numericArray1 = [1, 3, 5, 7]
    let numericArray2 = [2, 4, 6, 7, 8]
    let numericArray3 = [2, 9, 6, 10, 8]
    let numericArray4: Array<Int>? = nil
    
    let combinedNumericArray = Array(combine(numericArray1, numericArray2, numericArray3, numericArray4)).sorted()

    // Result: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Answer 3

这通常称为union,在Swift中可以使用Set:

let a = [1, 2, 3]
let b = [3, 4, 5]

let set = Set(a)
let union = set.union(b)

然后你可以将集合转换为数组:

let result = Array(union)

Answer 4

斯威夫特 4.0 版本

extension Array where Element : Equatable {

  public mutating func mergeElements<C : Collection>(newElements: C) where C.Iterator.Element == Element{
    let filteredList = newElements.filter({!self.contains($0)})
    self.append(contentsOf: filteredList)
  }

}

如前所述：传递给函数的数组是将从最终数组中省略的对象数组