数组 – Swift – 按属性获取数组中的对象

参见英文答案 > Find Object with Property in Array                                    5个
我是Swift的新手,我在按属性检索数组中的对象时遇到了一些问题.

请注意,我使用的是Swift 2.0.

我有以下数组;

//Dummy Data prior to database call:
static var listPoses = [
    YogaPose(id: 1, title: "Pose1", description: "This is a Description 1", difficulty: Enums.Difficulty.Beginner, imageURL: "Images/Blah1"),
    YogaPose(id: 2, title: "Pose2", description: "This is a Description 2", difficulty: Enums.Difficulty.Advanced, imageURL: "Images/Blah2"),
    YogaPose(id: 3, title: "Pose3", description: "This is a Description 3", difficulty: Enums.Difficulty.Intermediate, imageURL: "Images/Blah3"),
    YogaPose(id: 3, title: "Hello World", description: "This is a Description 3", difficulty: Enums.Difficulty.Intermediate, imageURL: "Images/Blah3")
]

我现在有一个方法,我想通过Id返回一个对象.有人可以告诉我如何这样做……例如其中listPose.Id === Id;

//Returns a single YogaPose By Id:
class func GetPosesById(Id: Int) -> YogaPose{


    if(listPoses.count > 0){
        return listPoses() ...
    }

}

因此,Swift提供了一种根据所需条件过滤对象列表的方法.

在这种情况下,您将需要使用过滤功能：

class func GetPosesById(Id: Int) -> YogaPose?{
    return listPoses.filter({ $0.id == Id }).first
}

基本上,过滤器函数将循环遍历整个listPoses并返回[YogaPose].代码({$0.id == Id})是你的条件,$0表示循环中的当前对象.

我也稍微改变了你的功能签名

class func GetPosesById(Id: Int) -> YogaPose

至

class func GetPosesById(Id: Int) -> YogaPose?

因为第一个属性是一个可选对象,您需要在以后解包