Swift3.0基础语法学习<五>

异常处理：

 //
 //  ViewController5.swift
 //  SwiftBasicDemo
 //
 //  Created by 思 彭 on 16/11/16.
 //  Copyright © 2016年 思 彭. All rights reserved.

 // 错误处理

 import UIKit

 class ViewController5: UIViewController {

     override func viewDidLoad() {
         super.viewDidLoad()
         self.title = "错误处理"

         // 1.函数内的 throws异常处理
         func send(job: Int, toPrinter printrName: String) throws ->String {
             if  printrName == "Never Has Toner" {
                 throw PrintError.noToner
             }
             return  "Job sent"
         }

         // 2.do...catch处理异常   输出： Job sent
         do {

             let  printerresponse = try send(job: , toPrinter: "Bi Sheng")
             print(printerresponse)
         }catch {
             print("error = \(error)")
         }

         // 3.
         do {
             let printerResponse = try send(job: , toPrinter: "Gutenberg")
             print(printerResponse)
         } catch PrintError.onFire {
             print("I'll just put this over here, with the rest of the fire.")
         } catch let printerError as PrintError {
             print("Printer error: \(printerError).")
         } catch {
             print(error)
         }
     }

     // 定义“打印错误”的枚举
     enum PrintError: Error {
         case outOfPaper
         case noToner
         case onFire
     }
 }