swift中block的简单使用

var finishBlock: ((_ mm :String )->String)? override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view,typically from a nib. // load { (msg) -> String in // // return "hahh" // } // self.finishBlock!("hhah") finishBlock = {(msg)->String in return "你好" }; let kj = finishBlock!("kkk") // print(kj) } func load(successed: @escaping (_ text :String )->String) { self.finishBlock = successed }