Objective-C是一种通用、高级、面向对象的编程语言。它扩展了标准的ANSI C编程语言，将Smalltalk式的消息传递机制加入到ANSI C中。使用IOS为框架实践基本的四则运算。-Objective-C is a general-purpose, high-level, object-oriented programming language. It extends the standard ANSI programming language C, the Smalltalk typ