追加后，数组为零

I have 2 Types, first is Car with property feature and it of the second type Feature.

我有2种类型,第一种是具有属性功能的Car,第二种是Feature。

I have a property cars: [Car], when I append new car to it, it returns nil.

我有一辆物业车:[汽车],当我把新车添加到它时,它返回零。

I have created a sample in the snippet below:

我在下面的代码段中创建了一个示例:

class Car {
    let make: String
    var features: Feature?
    let id: String

    init(make: String, features: Feature?, id: String) {
        self.make = make
        self.features = features
        self.id = id
    }
}

class Feature {
    let convertible: String

    init(convertible: String) {
        self.convertible = convertible
    }

}

var cars: [Car]?
var feature: Feature?

let featureElement = Feature(convertible: "yes")
feature = featureElement

let car = Car(make: "SomeMaked", features: feature, id: "ID")

cars?.append(car)

print(cars)

My question is: Shouldn't the array increase its count after appening to it? What am I missing?

我的问题是:数组在加到它之后不应该增加它的数量吗?我错过了什么?

Please note that this code is just sample, so ignore typos and coding convention.

请注意,此代码只是示例,因此请忽略拼写错误和编码约定。

1 个解决方案

#1

You haven't initialized your array.

您尚未初始化阵列。

Replace your var cars: [Car]? with var cars: [Car]? = []

更换你的变种车:[汽车]?与var车:[汽车]? = []

#1