var smallNumber = 4;
In that expression, a token, or reserved word—var—is followed by other tokens, such as an identifier (smallNumber), an operator (=), and a literal (4). (You learn more about these elements throughout the rest of the book.) The purpose of this expression is to set the variable named smallNumber equal to the integer 4.
Open a web browser.
In the address bar, type the following code and press Enter:
After you press Enter, you see a dialog box similar to this one: