Swift：数组检查索引处的对象

Question

我有一个具有多个属性的数据模型对象。我有一个动态数组，它有时会包含一些但不是全部的对象属性。

我如何安全地检查数组是否在它的索引处

数据模型

class Order{
     var item0:String?
     var item1:String?
     var item2:String?
}

数组：

var myArray = [String]()

guard 语句是我在检查数组中是否有不同索引处的元素时遇到问题的地方。

顺便说一句，数组中的元素永远不会超过 3 个。

let order = Order()
order.item0 = "hat"
order.item1 = "sneakers"

myArray.append(order.item0)
myArray.append(order.item1)
//sometimes there may or may not be item2

let placedOrder = Order

//These guard statements aren't working
guard case let placedOrder.item0 = myArray[0] else {return}

guard case let placedOrder.item1 = myArray[1] else {return}

//There isn't anything at myArray[2] but I need to safely check anyway
guard case let placedOrder.item2 = myArray[2] else {return}

Answer 1

1st 数组应该包含数据模型类型而不是它的属性：

var orders = [Order]() 
//changed the array's name from myArray to orders instead

2nd 将数据模型对象添加到数组中：

let orderOne = Order()

orders.append(orderOne)

第 3 次遍历数组，检查元素的属性是否为 nil：

for order in orders{

    if order.item0 != nil{
       //do something with order.item0
    }

    if order.item1 != nil{
       //do something with order.item1
    }

    if order.item2 != nil{
       //do something with order.item2
    }
}

Swift：数组检查索引处的对象

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