Welcome to C#1—a powerful computer-programming language that’s used to build substantial computer applications. There are billions of personal computers in use and an even larger number of mobile devices with computers at their core. Since it was released in 2001, C# has been used primarily to build applications for personal computers and systems that support them. The explosive growth of mobile phones, tablets and other devices also is creating significant opportunities for programming mobile apps. With this new sixth edition of C# 6 for Programmers, you’ll be able to use Microsoft’s new Universal Windows Platform (UWP) with Windows 10 to build C# apps for both personal computers and Windows 10 Mobile devices. With Microsoft’s purchase of Xamarin, you also can develop C# mobile apps for Android devices and for iOS devices, such as iPhones and iPads.