摘要：
//: Playground - noun: a place where people can playimport UIKitvar str = "Hello"var newString = str + "Lucy"var newTypeString = NSString(string: newS... 阅读全文
摘要：
import UIKitclass ViewController: UIViewController { var time = 0 func result(){ time++ print(time) } override func ... 阅读全文