Java Reference
In-Depth Information
Chapter 2
Language basics
2.1 Introduction
If you buy one of those do-it-yourself furniture kits, the best way to start is to
just dump all of those screws, nuts, planks, tools and other odd looking widgets
on the floor, group them into piles of similar looking items, and then go read the
instructions. Even if you don't know what all of those widgets are for, it helps to
pick them up and look them over so that you become familiar with them and can
recognize them in the instructions.
So rather than dribbling them out over several chapters, here we dump out
most of the basic widgets needed to construct Java programs. The goal is to
start to become familiar with Java's symbols, keywords, operators, expressions,
and other building blocks of the language with which to construct programs. We
provide examples and starter programs (on the Web Course) that allow you to
begin to write programs without needing to understand yet all of these language
elements at a deep level. You should refer back to this chapter as you proceed
and as your understanding of the language increases.
Note that in this chapter we occasionally mention the terms class , method , and
object .Ifyou are new to object-oriented programming, do not worry about these
terms for now. We discuss them in detail in the following chapters.
We begin with a listing of the basic elements and then outline the structure of
a generic program. We proceed through the individual elements of the language
beginning with the Java reserved words, or keywords .Wethen discuss the basic
data types in Java called primitives . These are used in expressions and with
various operators to create statements.
With regard to technical programming, we look at the floating-point represen-
tations in Java and the various issues regarding them. We also discuss the math
functions available in the core language.
2.2 Language elements and structures
Like any computer language, Java consists of a set of basic elements that the
programmer arranges according to the syntax of the language to build a program.
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