Often, books that teach Java provide their own package of classes. One reason for doing this is that it makes it easy to provide a class that facilitates the reading of a value of some primitive type from the keyboard.

Although this approach has its advantages, it is also inconvenient for students:

• if a student has their own computer, they have to obtain the package and install it;
• if they read more than one book, they have to become familiar with more than one package;
• they can easily fall into the trap of always using a book's package and never shifting to using the classes defined in Java's Core APIs.

In this course, the horrors of Java's keyboard input are introduced early:

BufferedReader tKeyboard = new BufferedReader(new InputStreamReader(System.in));
String tHeightString = tKeyboard.readHeightString();
double tHeight = Double.parseDouble(tHeightString);

Note the use of both instance methods and class methods and the need to use the wrapper classes of the primitive types.