In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "To be able to write tests for your code, you need to import the module with the @testable keyword."

A block of code is set as follows:

func makeHeadline(string: String) -> String {
  return "This Is A Test Headline"
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

override func setUp() {
  super.setUp()   
  viewController = ViewController()
}

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "To edit the build scheme, click on scheme on the toolbar in Xcode, and then click on Edit Scheme…."