Swift3.0 类型转换 示例

//
//  ViewController.swift
//  test_Swift3.0_type_casting
//
//  Created by jeffasd on 17/3/14.
//  Copyright © 2017年 jeffasd. All rights reserved.
//

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func touchesBegan(_ touches: Set, with event: UIEvent?) {
        var obj: Any;
        obj = "hello world";
        
        if obj is String {
            print("obj is String")
        }
        
        var things = [Any]();
        things.append(0);
        things.append(0.0)
        things.append(42)
        things.append(3.14)
        things.append("hello world")
        things.append( (3.0, 4.0) )
        things.append({
            (name: String) -> String in
            "hello, \(name)"
        })
        
        for thing in things {
            print("the thing is \(thing)")
            switch thing {
            case 0 as Int:
                print("zero as an Int")
            case 0 as Double:
                print("zero as a Double")
            case let someInt as Int:
                print("an integer value of \(someInt)")
            case let someDouble as Double where someDouble > 0:
                print("a positive double value of \(someDouble)")
            case is Double:
                print("some other double value that I don't want to print")
            case let someString as String:
                print("a string value of \"\(someString)\"")
            case let (x, y) as (Double, Double):
                print("an (x, y) point at \(x), \(y)")
            case let stringConverter as (String) -> String:
                print(stringConverter("Michael"))
            default:
                print("something else")
            }
        }
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}