How Java Relates to C and C++

Java is directly related to both C and C++. Java inherits its syntax from C. Its object model is adapted from C++. Java’s relationship with C and C++ is important for several reasons. First,
many programmers are familiar with the C/C++ syntax. This makes it easy for a C/C++ programmer to learn Java and, conversely, for a Java programmer to learn C/C++.

Second, Java’s designers did not “reinvent the wheel.” Instead, they further refined an
already highly successful programming paradigm. The modern age of programming began with C. It moved to C++, and now to Java. By inheriting and building upon that rich heritage, Java provides a powerful, logically consistent programming environment that takes the best of the past and adds new features required by the online environment. Perhaps most important, because of their similarities, C, C++, and Java define a common, conceptual framework for
the professional programmer. Programmers do not face major rifts when switching from one language to another.

One of the central design philosophies of both C and C++ is that the programmer is in charge! Java also inherits this philosophy. Except for those constraints imposed by the Internet environment, Java gives you, the programmer, full control. If you program well, your program reflect it. If you program poorly, your programs reflect that, too. Put differently, Java is not a language with training wheels. It is a language for professional programmers.

Java has one other attribute in common with C and C++: it was designed, tested, and refined
by real, working programmers. It is a language grounded in the needs and experiences of the people who devised it. There is no better way to produce a top-flight professional programming language.

Because of the similarities between Java and C++, especially their support for objectoriented programming, it is tempting to think of Java as simply the “Internet version of C++.” However, to do so would be a mistake. Java has significant practical and philosophical differences. Although Java was influenced by C++, it is not an enhanced version of C++. For example, it is neither upwardly nor downwardly compatible with C++. Of course, the similarities with C++ are significant, and if you are a C++ programmer, you will feel right at home with Java.

Another point: Java was not designed to replace C++. Java was designed to solve a certain set of problems. C++ was designed to solve a different set of problems. Both will coexist for many years to come.

The Origins of Java

Computer language innovation is driven forward by two factors: improvements in the art of programming and changes in the computing environment. Java is no exception. Building upon the rich legacy inherited from C and C++, Java adds refinements and features that reflect the current state of the art in programming. Responding to the rise of the online environment, Java offers features that streamline programming for a highly distributed architecture.

Java was conceived by James Gosling, Patrick Naughton, Chris Warth, Ed Frank, and Mike Sheridan at Sun Microsystems in 1991. This language was initially called “Oak” but was renamed “Java” in 1995. Somewhat surprisingly, the original impetus for Java was not the Internet! Instead, the primary motivation was the need for a platform-independent language that could be used to create software to be embedded in various consumer electronic devices, such as toasters, microwave ovens, and remote controls. As you can probably guess, many different types of CPUs are used as controllers. The trouble was that most computer languages are designed to be compiled for a specific target. For example, consider C++.

Although it is possible to compile a C++ program for just about any type of CPU, to do so requires a full C++ compiler targeted for that CPU. The problem, however, is that compilers are expensive and time-consuming to create. In an attempt to find a better solution, Gosling and others worked on a portable, cross-platform language that could produce code that would run on a variety of CPUs under differing environments. This effort ultimately led to the creation of Java.

About the time that the details of Java were being worked out, a second, and ultimately more important, factor emerged that would play a crucial role in the future of Java. This second force was, of course, the World Wide Web. Had the Web not taken shape at about the same time that Java was being implemented, Java might have remained a useful but obscure language for programming consumer electronics. However, with the emergence of the Web, Java was propelled to the forefront of computer language design, because the Web, too, demanded portable programs.

Most programmers learn early in their careers that portable programs are as elusive as they are desirable. While the quest for a way to create efficient, portable (platform-independent) programs is nearly as old as the discipline of programming itself, it had taken a back seat to other, more pressing problems. However, with the advent of the Internet and the Web, the old problem of portability returned with a vengeance. After all, the Internet consists of a diverse, distributed universe populated with many types of computers, operating systems, and CPUs. 

What was once an irritating but a low-priority problem had become a high-profile necessity. By 1993 it became obvious to members of the Java design team that the problems of portability frequently encountered when creating code for embedded controllers are also found when attempting to create code for the Internet. This realization caused the focus of Java to switch from consumer electronics to Internet programming. So, while it was the desire for an architecture-neutral programming language that provided the initial spark, it was the Internet that ultimately led to Java’s large-scale success.

The Second Java Revolution

Java 2 Platform Standard Edition, version 5 (J2SE 5) marks the beginning of the second Java revolution. J2SE 5 adds many new features to Java that fundamentally change the character of the language, increasing both its power and its range. So profound are these additions that they will forever alter the way that Java code is written. J2SE 5 is a revolutionary force that cannot be ignored.

To give you an idea of the scope of the changes caused by J2SE 5, here is a list of its major new features covered in this book:

● Generics

● Autoboxing/unboxing

● Enumerations

● The enhanced, “for-each” style for loop

● Variable-length arguments (varargs)

● Static import

● Metadata (annotations)

This is not a list of minor tweaks or incremental upgrades. Each item in the list represents a significant addition to the Java language. Some, such as generics, the enhanced for, and varargs, introduce new syntax elements. Others, such as autoboxing and auto-unboxing, alter the semantics of the language. Metadata adds an entirely new dimension to programming. In all cases, substantial functionality has been added. 

The importance of these new features is reflected in the use of the version number 5. The next version number for Java would normally have been 1.5. However, the changes and new features are so significant that a shift from 1.4 to 1.5 just didn’t seem to express the magnitude of the change. Instead, Sun elected to increase the version number to 5 as a way of emphasizing that a major event was taking place. Thus, the current product is called J2SE 5, and the developer’s kit is called JDK 5. However, in order to maintain consistency, Sun decided to use 1.5 as its internal version number. Thus, 5 is the external version number and 1.5 is the internal version number.

Because of Sun’s use of 1.5 as the internal version number, when you ask the compiler its version, it will respond with 1.5 rather than 5. Also, the online documentation supplied by Sun uses 1.5 to refer to features added by the J2SE 5. In general, whenever you see 1.5, it simply means 5.

The Evolution of Java

Only a few languages have fundamentally reshaped the very essence of programming. In this elite group, one stands out because its impact was both rapid and widespread. This language is, of course, Java. It is not an overstatement to say that the original release of Java 1.0 in 1995 by Sun Microsystems caused a revolution in programming. This revolution radically transformed the Web into a highly interactive environment. In the process, Java set a new standard in computer language design.

Over the years, Java continued to grow, evolve, and otherwise redefine itself. Unlike many other languages, which are slow to incorporate new features, Java has continually been at the forefront of computer language design. One reason for this is the culture of innovation and change that came to surround Java. As a result, Java has gone through several upgrades—some relatively small, others more significant.

The first major update to Java was version 1.1. The features added by Java 1.1 were more substantial than the small increase in the version number would have you think. For example, Java 1.1 added many new library elements, redefined the way events are handled, and

reconfigured many features of the original 1.0 library.

The next major release of Java was Java 2, where the 2 indicates “second generation.” The creation of Java 2 was a watershed event, marking the beginning of Java’s “modern age.”

The first release of Java 2 carried the version number 1.2. It may seem odd that the first release of Java 2 used the 1.2 version number. The number originally referred to the internal version number of the Java libraries, but then was generalized to refer to the entire release, itself. With Java 2, Sun repackaged the Java product as J2SE (Java 2 Platform Standard Edition), and the version numbers began to be applied to that product. The next upgrade of Java was J2SE 1.3. This version of Java was the first major upgrade to the original Java 2 release. For the most part it added to existing functionality and “tightened up” the development environment. The release of J2SE 1.4 further enhanced Java.

This release contained several important new features, including chained exceptions,  channelbased I/O, and the assert keyword. The latest release of Java is J2SE 5. As important as each of the preceding upgrades to Java have been, none compares in scale, size, and scope to that of J2SE 5. It has fundamentally reshaped the Java world!

What is Java?

Java is the preeminent language of the Internet. Moreover, it is the universal language of Web programmers around the world. To be a professional Web developer today implies proficiency in Java. Therefore, if Internet-based programming is in your future, you have chosen the right language to learn—and, this book will help you learn it.The purpose of this book is to teach you the fundamentals of Java programming. It uses a step-by-step approach complete with numerous examples, self-tests, and projects. It assumes no previous programming experience. The book starts with the basics, such as how to compile and run a Java program. It then discusses every keyword in the Java language. It concludes with some of Java’s most advanced features, such as multithreaded programming, generics, and applets. By the time you finish, you will have a firm grasp of the essentials of Java programming.

It is important to state at the outset that this book is just a starting point. Java is more than 
just the elements that define the language. Java also includes extensive libraries and tools that 
aid in the development of programs. Furthermore, Java provides a sophisticated set of libraries
that handle the browser user interface. To be a top-notch Java programmer implies mastery of
these areas, too. After completing this book, you will have the knowledge to pursue any and all other aspects of Java.