arrays - 如何根据名称数组过滤数组？

Question

我有 2 个数组。在第一个数组中，我有一个要从第二个数组中删除的名单。

第一个数组只是字符串数组:

var arrayNames = ["apple", "apricot", "cucumber"]

第二个数组是自定义结构的数组:

struct fruitsData {
var name: String?
}

var secondArray = [fruitsData(name: "apple"),fruitsData(name: "apricot"), fruitsData(name: "mango"), fruitsData(name: "grapes"), fruitsData(name: "tomato"), fruitsData(name: "lichi"), fruitsData(name: "cucumber"), fruitsData(name: "brinjal")]

那么我怎样才能得到只包含这些数据的数组:

var finalData = [fruitsData(name: "mango"), fruitsData(name: "grapes"), fruitsData(name: "tomato"), fruitsData(name: "lichi"), fruitsData(name: "brinjal")]

哪个不包含 arrayNames 中的任何名称？

Answer 1

有几种方法可以做到这一点:

• 最好的方法是使用 filter 方法:

  var arrayNames = ["apple", "apricot", "cucumber"]
  var secondArray = [fruitsData(name: "apple"),fruitsData(name: "apricot"), fruitsData(name: "mango"), fruitsData(name: "grapes"), fruitsData(name: "tomato"), fruitsData(name: "lichi"), fruitsData(name: "cucumber"), fruitsData(name: "brinjal")]
  
  secondArray = secondArray.filter({$0.name != nil && !arrayNames.contains($0.name!)})
  

• 或者，如果您想为了可读性而牺牲效率，您可以将 for-in 循环与辅助数组一起使用:

  var arrayNames = ["apple", "apricot", "cucumber"]
  var secondArray = [fruitsData(name: "apple"),fruitsData(name: "apricot"), fruitsData(name: "mango"), fruitsData(name: "grapes"), fruitsData(name: "tomato"), fruitsData(name: "lichi"), fruitsData(name: "cucumber"), fruitsData(name: "brinjal")]
  var helperArray = [fruitsData]()
  
  for fruit in secondArray {
  
      if fruit.name != nil && !arrayNames.contains(fruit.name!){
          helperArray.append(fruit)
      }
  
  }
  
  secondArray = helperArray
  

上面的代码将从 secondArray 中删除其名称包含在 arrayNames 中的每个元素。您应该熟悉 Map, Filter and Reduce .