This exercise demonstrates how functions are called, and how functions are actually objects in JavaScript. The JavaScript in this page contains some functions that you can call from the browser Developer Tools console. The Developer Tools Console is available in the Edge, Chrome and Chromium browsers.
To open Developer Tools in the browser press the F12 key. If your keyboard does not have that key, hold down the CTRL and SHIFT keys and press J
The console will appear on the right of the page. You may need to confirm that you want to open it.
You can find the steps to follow for the exercise in Chapter 1 of the book in the section "Make Something Happen - Explore functions in the console"