ios-Swift处理异常的三种方式

1、我们手动的去捕捉异常

        let jsonStr="lll"
        
        let jsonData=jsonStr.data(using: String.Encoding.utf8)
        
        //在Swift中options是存放在数组中，如果我们不想写，直接传入一个空数组就可以
        do
        {
        let result = try JSONSerialization.jsonObject(with: jsonData!, options: [JSONSerialization.ReadingOptions.mutableContainers,JSONSerialization.ReadingOptions.mutableLeaves])
          print(result)
        }
        catch
        {
            print(error)
        }

2、try?尝试try，系统帮我们处理异常，如果发生了异常则会返回nil，如果没有异常就返回相应的对象

let result = try? JSONSerialization.jsonObject(with: jsonData!, options: [JSONSerialization.ReadingOptions.mutableContainers,JSONSerialization.ReadingOptions.mutableLeaves])
 print(result)

3、try! 是强行try，意思就是直接的说不会有异常，如果出现异常则程序会崩溃

 let result = try! JSONSerialization.jsonObject(with: jsonData!, options: [JSONSerialization.ReadingOptions.mutableContainers,JSONSerialization.ReadingOptions.mutableLeaves])
        print(result)