在swift 3.0中将坐标数组转换为geojson字符串

import Foundation

struct Coordinate {
    var latitude: Double
    var longitude: Double
}

func convertToGeoJSON(coordinates: [Coordinate]) -> String? {
    var featureCollection: [String: Any] = [
        "type": "FeatureCollection",
        "features": []
    ]
    
    for coordinate in coordinates {
        let feature: [String: Any] = [
            "type": "Feature",
            "geometry": [
                "type": "Point",
                "coordinates": [coordinate.longitude, coordinate.latitude]
            ],
            "properties": [:]
        ]
        
        featureCollection["features"]?.append(feature)
    }
    
    do {
        let jsonData = try JSONSerialization.data(withJSONObject: featureCollection, options: [])
        let jsonString = String(data: jsonData, encoding: .utf8)
        return jsonString
    } catch {
        print("Error converting to GeoJSON: \(error)")
        return nil
    }
}

// Example usage:
let coordinates = [
    Coordinate(latitude: 37.7749, longitude: -122.4194),
    Coordinate(latitude: 34.0522, longitude: -118.2437),
    Coordinate(latitude: 40.7128, longitude: -74.0060)
]

if let geoJSONString = convertToGeoJSON(coordinates: coordinates) {
    print(geoJSONString)
} else {
    print("Failed to convert coordinates to GeoJSON")
}