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 type of the message passing mechanism is added to the ANSI C. The use of IOS framework for the practice of four basic computing.