Question

我想知道是否有任何有效的方法来过滤自定义对象的数组，例如我下面的方法。我有一个Author类和一个Book类，可以有多个具有不同属性的作者，例如书状态的枚举，作者写的书注释以及书状态发生变化的数组。我想按不同的状态，作者和日期进行过滤，其中所有4个参数都是可选的。

class Author : Equatable {
   let name : String
   let id = UUID()
}

class Book : Equatable {
   let date = Date()
   var comments : [Comment] = []
   var writtenBy : [Author] = []
   var state : State = .available {
       didSet {
            updateState(timestamp: Date())
        }
    }
}

enum State : String, CaseIterable {
    case available
    case unavailable
    case missing
}


class CollectionOfBooks {
    private static var arrayOfBooks : [Book] = []

    static func getAllBooks(state: State?, authorId: UUID?, fromDate: Date?, toDate : Date?) -> [Book] {


    let filteredArray = arrayOfBooks.filter({$0.state == state})
    filteredArray = arrayOfBooks.filter....
    filteredArray = arrayOfBooks.filter....
    filteredArray = arrayOfBooks.filter....

return filtered array 

 // what is the most efficient way of sorting the my array? 
//At the moment i only know how to achieve this by filtering one parameter at a time. 
    }
}

Answer 1

您可以在一个条件中合并所有条件。

<div *ngIf="gotDataMapping">Content to render when condition is true.</div>

快速过滤数组中的自定义对象

1 个答案: