Java in a Nutshell, 5th Edition

C++ Features Not Found in Java

This chapter indicates similarities and differences between Java and C++ in footnotes. Java shares enough concepts and features with C++ to make it an easy language for C++ programmers to pick up. Several features of C++ have no parallel in Java, however. In general, Java does not adopt those features of C++ that make the language significantly more complicated.

C++ supports multiple inheritance of method implementations from more than one superclass at a time. While this seems like a useful feature, it actually introduces many complexities to the language. The Java language designers chose to avoid the added complexity by using interfaces instead. Thus, a class in Java can inherit method implementations only from a single superclass, but it can inherit method declarations from any number of interfaces.

C++ supports templates that allow you, for example, to implement a Stack class and then instantiate it as Stack<int> or Stack<double> to produce two separate types: a stack of integers and a stack of floating-point values. Java 5.0 introduces parameterized types or “generics” that provide similar functionality in a more robust fashion. Generics are covered in Chapter 4.

C++ allows you to define operators that perform arbitrary operations on instances of your classes. In effect, it allows you to extend the syntax of the language. This is a nifty feature, called operator overloading, that makes for elegant examples. In practice, however, it tends to ...