我已经创建了下一个字典:
var postJSON = [ids[0]:answersArray[0], ids[1]:answersArray[1], ids[2]:answersArray[2]] as Dictionary
得到:
[2: B, 1: A, 3: C]
那么,如何将其转换为JSON呢?
我已经创建了下一个字典:
var postJSON = [ids[0]:answersArray[0], ids[1]:answersArray[1], ids[2]:answersArray[2]] as Dictionary
得到:
[2: B, 1: A, 3: C]
那么,如何将其转换为JSON呢?
当前回答
这是一个简单的扩展来做到这一点:
https://gist.github.com/stevenojo/0cb8afcba721838b8dcb115b846727c3
extension Dictionary {
func jsonString() -> NSString? {
let jsonData = try? JSONSerialization.data(withJSONObject: self, options: [])
guard jsonData != nil else {return nil}
let jsonString = String(data: jsonData!, encoding: .utf8)
guard jsonString != nil else {return nil}
return jsonString! as NSString
}
}
其他回答
你的假设是错误的。只是因为调试器/Playground用方括号显示你的字典(这是Cocoa显示字典的方式),这并不意味着这是JSON输出格式化的方式。
下面是将字符串字典转换为JSON的示例代码:
Swift 3版本:
import Foundation
let dictionary = ["aKey": "aValue", "anotherKey": "anotherValue"]
if let theJSONData = try? JSONSerialization.data(
withJSONObject: dictionary,
options: []) {
let theJSONText = String(data: theJSONData,
encoding: .ascii)
print("JSON string = \(theJSONText!)")
}
要以“漂亮打印”的格式显示上面的内容,你可以将选项行更改为:
options: [.prettyPrinted]
或者在Swift 2语法中:
import Foundation
let dictionary = ["aKey": "aValue", "anotherKey": "anotherValue"]
let theJSONData = NSJSONSerialization.dataWithJSONObject(
dictionary ,
options: NSJSONWritingOptions(0),
error: nil)
let theJSONText = NSString(data: theJSONData!,
encoding: NSASCIIStringEncoding)
println("JSON string = \(theJSONText!)")
它的输出是
"JSON string = {"anotherKey":"anotherValue","aKey":"aValue"}"
或者用漂亮的格式:
{
"anotherKey" : "anotherValue",
"aKey" : "aValue"
}
正如您所期望的那样,在JSON输出中,字典用花括号括起来。
编辑:
在Swift 3/4语法中,上面的代码看起来像这样:
let dictionary = ["aKey": "aValue", "anotherKey": "anotherValue"]
if let theJSONData = try? JSONSerialization.data(
withJSONObject: dictionary,
options: .prettyPrinted
),
let theJSONText = String(data: theJSONData,
encoding: String.Encoding.ascii) {
print("JSON string = \n\(theJSONText)")
}
}
你问题的答案如下:
斯威夫特2.1
do {
if let postData : NSData = try NSJSONSerialization.dataWithJSONObject(dictDataToBeConverted, options: NSJSONWritingOptions.PrettyPrinted){
let json = NSString(data: postData, encoding: NSUTF8StringEncoding)! as String
print(json)}
}
catch {
print(error)
}
斯威夫特5:
let dic = ["2": "B", "1": "A", "3": "C"]
let encoder = JSONEncoder()
if let jsonData = try? encoder.encode(dic) {
if let jsonString = String(data: jsonData, encoding: .utf8) {
print(jsonString)
}
}
注意键和值必须实现Codable。字符串、整型和双精度(以及更多)已经是可编码的。参见编码和解码自定义类型。
还要注意,Any不符合Codable。这可能仍然是一个很好的方法来调整你的数据成为可编码的,这样你就可以使用Swift类型(特别是在你也要解码任何编码的json的情况下),这样你就可以更声明你的编码的结果。
我对你的问题的回答如下
let dict = ["0": "ArrayObjectOne", "1": "ArrayObjecttwo", "2": "ArrayObjectThree"]
var error : NSError?
let jsonData = try! NSJSONSerialization.dataWithJSONObject(dict, options: NSJSONWritingOptions.PrettyPrinted)
let jsonString = NSString(data: jsonData, encoding: String.Encoding.utf8.rawValue)! as String
print(jsonString)
答案是
{
"0" : "ArrayObjectOne",
"1" : "ArrayObjecttwo",
"2" : "ArrayObjectThree"
}
这是一个简单的扩展来做到这一点:
https://gist.github.com/stevenojo/0cb8afcba721838b8dcb115b846727c3
extension Dictionary {
func jsonString() -> NSString? {
let jsonData = try? JSONSerialization.data(withJSONObject: self, options: [])
guard jsonData != nil else {return nil}
let jsonString = String(data: jsonData!, encoding: .utf8)
guard jsonString != nil else {return nil}
return jsonString! as NSString
}
}