The authors make a good choice of java, as the teaching language of this book. It conveys to students the main aspects of being a professional programmer. These days, that usually involves object oriented programming. And java was explicitly designed from scratch to be fully OO, unlike C++.

Also, much current programming involves making a GUI. Well in java, this is quite simple, as shown by various chapters. The reader quickly gets up to speed in coding simple graphics, with numerous types of widgets. Also, the use of widgets and graphics coding is inherently OO. So this reinforces the book's teachings about OO. To a new student [new to any programming], OO principles can seem rather abstract. Coding widgets helps solidify the principles.