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What is JAVA?
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Java (with a capital J) is a high-level, third generation
programming language, like C, Fortran, Smalltalk, Perl, and many
others. You can use Java to write computer applications that crunch
numbers, process words, play games, store data or do any of the
thousands of other things computer software can do.
Compared to other programming languages, Java is most similar to C.
However although Java shares much of C's syntax, it is not C.
Knowing how to program in C or, better yet, C++, will certainly help
you to learn Java more quickly, but you don't need to know C to
learn Java. Unlike C++ Java is not a superset of C. A Java compiler
won't compile C code, and most large C programs need to be changed
substantially before they can become Java programs.
What's most special about Java in relation to other programming
languages is that it lets you write special programs called applets
that can be downloaded from the Internet and played safely within a
web browser. Traditional computer programs have far too much access
to your system to be downloaded and executed willy-nilly. Although
you generally trust the maintainers of various ftp archives and
bulletin boards to do basic virus checking and not to post
destructive software, a lot still slips through the cracks. Even
more dangerous software would be promulgated if any web page you
visited could run programs on your system. You have no way of
checking these programs for bugs or for out-and-out malicious
behavior before downloading and running them.
Java solves this problem by severely restricting what an applet can
do. A Java applet cannot write to your hard disk without your
permission. It cannot write to arbitrary addresses in memory and
thereby introduce a virus into your computer. It should not crash
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