[作業]回傳 JSON 格式資料的有趣第三方 API，讀取資料做一個 App：有貓膩

import UIKit
import Kingfisher
private let reuseIdentifier = "CatCollectionViewCell"
class CatCollectionViewController: UICollectionViewController {
    var cats: [Cat] = []
    override func viewDidLoad() {
        super.viewDidLoad()
        var request = URLRequest(url: URL(string: "https://api.thecatapi.com/v1/Favourites")!, cachePolicy: .returnCacheDataElseLoad, timeoutInterval: 3)
        request.setValue("DEMO-API-KEY", forHTTPHeaderField: "x-api-key")
        URLSession.shared.dataTask(with: request) { data, response, error in
            if let data, let response = response as? HTTPURLResponse, response.statusCode == 200, error == nil {
                let decoder = JSONDecoder()
                decoder.keyDecodingStrategy = .convertFromSnakeCase
                do {
                    let catResponse = try decoder.decode([Cat].self, from: data)
                    DispatchQueue.main.async {
                        self.cats = catResponse
                        self.collectionView.reloadData()
                    }
                } catch {
                    print(error)
                }
            }
        }.resume()
    }
    // MARK: UICollectionViewDataSource
    override func numberOfSections(in collectionView: UICollectionView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 1
    }
    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of items
        return cats.count
    }
    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! CatCollectionViewCell
        let cat = cats[indexPath.item]
        cell.catImageView.kf.setImage(with: cat.image.url)
        return cell
    }
}

https://github.com/doriswlc/CatApp