There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "In the main.dart file, remove the example code."

A block of code is set as follows:

void main() {
 var name = "Dart";
 print ("Hello $name!");
}

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

return Stack(
   children: <Widget>[
      Positioned(
         child: Ball(), 
         top: posY,
         left: posX,
),

Any command-line input or output is written as follows:

cd hello_world 
flutter run

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "From the Android Studio File menu, select Open...."