In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text, folder names, filenames, and file extensions  are shown as follows:
"Double-click on the downloaded .dmg file and in the shown dialog, copy the Android Studio executable to the Applications directory."
A block of code is set as follows:
private void initialiseBluetooth() {
bluetoothManager =
(BluetoothManager)getSystemService
(Context.BLUETOOTH_SERVICE);
bluetoothAdapter = bluetoothManager.getAdapter();
bluetoothLeScanner = bluetoothAdapter.getBluetoothLeScanner();
}
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
bluetoothAdapter = bluetoothManager.getAdapter();
bluetoothLeScanner = bluetoothAdapter.getBluetoothLeScanner();
Any command-line, (including commands at the R console) input or output is written as follows:
$ npm install --save eddystone-beacon
New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Clicking the Next button moves you to the next screen."