Swift Is an open source programming language that supports multiple programming paradigms and compilers , Apple in 2014 year WWDC（ Apple Developer Conference ） release , Used to develop iOS,OS X and watchOS Applications .
Swift Combined C and Objective-C And is not affected by C Compatibility limitations .
Swift stay Mac OS and iOS The platform can communicate with Object-C Use the same operating environment .
2015 year 6 month 8 day , Apple in WWDC 2015 It was announced at the meeting that ,Swift Will open source , Including compilers and standard libraries .
Who is suitable for reading this tutorial ？
This tutorial is suitable for those who want to engage in mobile terminal (iphone) Develop or OS X Application programmers , It would be better if you had a programming foundation before .
This tutorial All instances are based on Xcode8.2.1（Swift 3.0.2 Syntax format ） Development testing .
first Swift Program
first Swift Of course, the program outputs "Hello, World!" start , The code is as follows ：
Run instance »
var myString = "Hello, World!" : use var Keyword defines a variable myString, The value is Hello, World!
print : The value of the output variable