Java in a Nutshell, 5th Edition [Electronic resources] نسخه متنی

Chapter 2. Java Syntax from the Ground Up

This chapter is a terse but comprehensive introduction to Java
syntax. It is written primarily for readers who are new to the
language but have at least some previous programming experience.
Determined novices with no prior programming experience may also find
it useful. If you already know Java, you should find it a useful
language reference. The chapter includes comparisons of Java to C and
C++ for the benefit of programmers coming from those languages.

This chapter documents the syntax of Java programs by starting at the
very lowest level of Java syntax and building from there, covering
increasingly higher orders of structure. It covers:

• The characters used to write Java programs and the encoding of those
  characters.

• Literal values, identifiers, and other tokens that comprise a Java
  program.

• The data types that Java can manipulate.

• The operators used in Java to group individual tokens into larger
  expressions.

• Statements, which group expressions and other statements to form
  logical chunks of Java code.

• Methods (also called functions, procedures, or subroutines), which
  are named collections of Java statements that can be invoked by other
  Java code.

• Classes, which are collections of methods and fields. Classes are the
  central program element in Java and form the basis for
  object-oriented programming. Chapter 3 is
  devoted entirely to a discussion of classes and
  objects.

• Packages, which are collections of related
  classes.

• Java programs, which consist of one or more interacting classes that
  may be drawn from one or more packages.

The syntax of most programming languages is complex, and Java is no
exception. In general, it is not possible to document all elements of
a language without referring to other elements that have not yet been
discussed. For example, it is not really possible to explain in a
meaningful way the operators and statements supported by Java without
referring to objects. But it is also not possible to document objects
thoroughly without referring to the operators and statements of the
language. The process of learning Java, or any language, is therefore
an iterative one. If you are new to Java (or a Java-style programming
language), you may find that you benefit greatly from working through
this chapter and the next

twice , so that you can
grasp the interrelated concepts.