我需要从文本文件中读取和写入数据,但我无法弄清楚如何.
我在Swift的iBook中找到了这个示例代码,但我仍然不知道如何编写或读取数据.
import Cocoa
class DataImporter
{
/*
DataImporter is a class to import data from an external file.
The class is assumed to take a non-trivial amount of time to initialize.
*/
var fileName = "data.txt"
// the DataImporter class would provide data importing functionality here
}
class DataManager
{
@lazy var importer = DataImporter()
var data = String[]()
// the DataManager class would provide data management functionality here
}
let manager = DataManager()
manager.data += "Some data"
manager.data …多年来，这个问题已经被问过很多次了，但它在 Swift 5 中再次发生了变化，尤其是在最近的两个测试版中。
读取 JSON 文件似乎很简单：
func readJSONFileData(_ fileName: String) -> Array<Dictionary<String, Any>> {
var resultArr: Array<Dictionary<String, Any>> = []
if let url = Bundle.main.url(forResource: "file", withExtension: "json") {
if let data = try? Data(contentsOf: url) {
print("Data raw: ", data)
if let json = try? (JSONSerialization.jsonObject(with: data, options: []) as! NSArray) {
print("JSON: ", json)
if let arr = json as? Array<Any> {
print("Array: ", arr)
resultArr = arr.map { $0 as! Dictionary<String, Any> …