Working with JSON in Swift

Apple 官方教學：
https://developer.apple.com/swift/blog/?id=37

Extracting Values from JSON

The JSONSerialization class method jsonObject(with:options:) returns a value of type Any and throws an error if the data couldn’t be parsed.

import Foundation

let data: Data // received from a network request, for example
let json = try? JSONSerialization.jsonObject(with: data, options: [])

// Example JSON with object root:
/*
	{
		"someKey": 42.0,
		"anotherKey": {
			"someNestedKey": true
		}
	}
*/
if let dictionary = jsonWithObjectRoot as? [String: Any] {
	if let number = dictionary["someKey"] as? Double {
		// access individual value in dictionary
	}

	for (key, value) in dictionary {
		// access all key / value pairs in dictionary
	}

	if let nestedDictionary = dictionary["anotherKey"] as? [String: Any] {
		// access nested dictionary values by key
	}
}

// Example JSON with array root:
/*
	[
		"hello", 3, true
	]
*/
if let array = jsonWithArrayRoot as? [Any] {
	if let firstObject = array.first {
		// access individual object in array
	}

	for object in array {
		// access all objects in array
	}

	for case let string as String in array {
		// access only string values in array
	}
}