Learn notes from scratch (Day 12)--say a few special operators

original articles, welcome reprint. Reprint Please specify: Dongsheng's blog

In addition to some commonly used operators, there are some others:

Reference number (. ): an instance invokes an operator such as a property, method, and so on.

question mark (? ): Used to declare an optional type.

exclamation point (! ): The optional type value is forced to be unpacked.

Arrow (): Describes the function or method return value type.

colon operator (:): Used for dictionary collections to split "key value" pairs.

......

Welcome to follow Dongsheng Sina Weibo@tony_Dongsheng.
Learn about the latest technical articles, books, tutorials and information on the public platform of the smart Jie classroom
650) this.width=650; "title=" 00.png "alt=" Wkiol1buc5oxjtzyaaas2mbeznc511.png "src=" http://s2.51cto.com/wyfs02/M02/ 7c/a0/wkiol1buc5oxjtzyaaas2mbeznc511.png "/>
More ProductsIOS,Cocos, mobile Design course please pay attention to the official website of Chi Jie Classroom:http://www.zhijieketang.com
Smart-Jie Classroom Forum Website:http://51work6.com/forum.php

This article is from the "Dongsheng-ios Technical Consultant" blog, make sure to keep this source http://tonyguan.blog.51cto.com/701759/1746098

Learn notes from scratch (Day 12)--say a few special operators