arrays - 如何初始化信息数组并追加

Question

我希望能够初始化一个空数组结构，该结构具有 .append() 的能力并且可以保存类似于以下的信息:

var locations = [
    ["title": "New York, NY",    "latitude": 40.713054, "longitude": -74.007228],
    ["title": "Los Angeles, CA", "latitude": 34.052238, "longitude": -118.243344],
    ["title": "Chicago, IL",     "latitude": 41.883229, "longitude": -87.632398]
]

这个数据类型是字典数组的数组吗？我希望能够通过 location 访问 title 、latitude 和 longitude 并且我从未使用过像这样，所以我不确定如何初始化和 .append()

Answer 1

您的结构是字典数组:[[String : Any]]。

正如@Hamish 在评论中建议的那样，最好将数据存储为结构数组。

这是一种可能的实现方式:

struct Location: CustomStringConvertible {
    var title: String
    var latitude: Double
    var longitude: Double

    var description: String { return "(title: \(title), latitude: \(latitude), longitude: \(longitude))"}
}

var locations = [
    Location(title: "New York, NY", latitude: 40.713054, longitude: -74.007228),
    Location(title: "Los Angeles, CA", latitude: 34.052238, longitude: -118.243344),
    Location(title: "Chicago, IL", latitude: 41.883229, longitude: -87.632398)
]

// Append a new location...    
locations.append(Location(title: "Boston, MA", latitude: 42.3601, longitude: -71.0589))

print(locations)

[(title: New York, NY, latitude: 40.713054, longitude: -74.007228),
(title: Los Angeles, CA, latitude: 34.052238, longitude: -118.243344),
(title: Chicago, IL, latitude: 41.883229, longitude: -87.632398),
(title: Boston, MA, latitude: 42.3601, longitude: -71.0589)]

func lookUp(title: String, in locations: [Location]) -> [Location] {
    return locations.filter { $0.title.range(of: title) != nil }
}

print(lookUp(title: "CA", in: locations))

[(title: Los Angeles, CA, latitude: 34.052238, longitude: -118.243344)]

print(lookUp(title: "Chicago", in: locations))

[(title: Chicago, IL, latitude: 41.883229, longitude: -87.632398)]