如何将自定义对象数组转换为字符串数组？

Question

我目前有一个自定义对象数组

[基因报告员]

定义如下：

public struct GenrePosters: Decodable, Equatable{

  public let poster : String

  public init? (json: JSON) {

    guard let poster: String = "poster_path" <~~ json
      else {return nil}
    self.poster = poster
  }

  public static func ==(lhs: GenrePosters, rhs: GenrePosters) -> Bool {
    return lhs.poster == rhs.poster
  }

当打印到console时，它如下所示：

[MyMovieGuide.GenrePosters（海报：/e1mjopzAS2KNsvpbpahQ1a6SkSn.jpg），MyMovieGuide.GenrePosters（海报：/jjbgi2r5crt36xf6inuehzsceb.jpg），MyMovieGuide.GenrePosters（海报：/tikfbxbzhsxpiitib5ws8vgxjt.jpg”）]

我正在尝试将genreposter数组转换为一个字符串数组，其中仅包含如下海报值：

[“/e1mjopzAS2KNsvpbpahQ1a6SkSn.jpg”“/jjBgi2r5cRt36xF6iNUEhzscEcb.jpg”“/tikfbxbxbzhsxpiitib5ws8vgxjt.jpg”]

任何帮助将不胜感激！

Answer 1

public struct GenrePosters: Decodable, Equatable{

    public let poster : String

    public init? (json: JSON) {

        guard let poster: String = "poster_path" <~~ json
            else {return nil}
        self.poster = poster
    }

    public static func ==(lhs: GenrePosters, rhs: GenrePosters) -> Bool {
        return lhs.poster == rhs.poster
    }
}

let genrePostersArray = [GenrePosters(poster: "one"), GenrePosters(poster: "two"), GenrePosters(poster: "three")]
let genrePostersStringArray = genrePostersArray.flatMap { $0.poster }
print(genrePostersStringArray) // ["one", "two", "three"]

Answer 2

您应该能够使用map（:）方法完成此操作：

let posters = posterList.map {$0.poster}