swift3.0 类似 oc 中 obj = nil 的判断

//
//  ViewController.swift
//  test_nil_swift
//
//  Created by jeffasd on 17/3/13.
//  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<UITouch>,with event: UIEvent?) {
        
        showName(nil);
        
        self.view.backgroundColor = UIColor.blue;
    }
    
    //MARK: swift3.0判断变量是否存在
    func showName(_ name: String?){
        
        if name != nil {
            print("name")
        }else{
            print("anme is nil")
        }
        
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}