One nice reason to use an online text is to leverage the power of
the very computer we seek to learn to program.
The program examples in your text are "live",
meaning they can be
executed as well as read, so you can see what the code you are
examining will do when a computer runs it.
In addition to running the examples, you can edit them...
make changes right there on the text web page. Then you can execute
the changed program and see what the changes cause to happen when
the code is run by computer.
Please look through the text and become familiar with this
nice aspect of it. We will examine these features in class.