[JAVA][Beginning Java 8 Games Development]

Chapter 3 ■ A Java 8 Primer: An Introduction to Java 8 Concepts and Principles
values of different sizes and resolutions. Integer values hold whole numbers, whereas a floating point value holds
fractional (decimal point value) numbers. It is important to use the right numeric data type for a variable’s scope, or
range, of use, because, as you can see in Binary Size column in Table 3-1, large numeric data types can use up to eight
times more memory than the smaller ones.
Table 3-1. Java Primitive Data Types, Along with Their Default Values, Size in Memory, Definition, and Numeric Range
Data Type Default Binary Size Definition Range
boolean false 1 bit True or false value 0 to 1 (false or true)
char \u0000 16 bit Unicode character \u0000 to \uFFFF
byte 0 8 bit Signed integer value –128 to 127 (256 total values)
short 0 16 bit Signed integer value –-32768 to 32767 (65,536 total values)
int 0 32 bit Signed integer value –2147483648 to 2147483647
long 0 64 bit Signed integer value –9223372036854775808 to
9223372036854775807
float 0.0 32 bit IEEE 754 floating point value ±1.4E-45 to ±3.4028235E+38
double 0.0 64 bit IEEE 754 floating point value ±4.9E-324 to
±1.7976931348623157E+308
Reference Data Types: Objects and Arrays
(OOP languages also have reference data types, which provide a reference in memory to another structure
containing a more complex data structure, such as an object or an array. These more complex data structures are
created using code; in the case of Java, this is a class. There are Java Array classes of various types that create arrays of
data (such as simple databases) as well as the constructor method in a Java class, which can create the object structure
in memory, containing both Java code (methods) and data (fields).
Java Operators: Manipulating Data in the Application
In this section, you will learn about some of the most commonly used operators in the Java programming language,
especially those that are the most useful for programming games. These include arithmetic operators, used for
mathematical expressions; relational operators, used to ascertain relationships (equal, not equal, greater than, less
than, and so on) between data values; logical operators, used for boolean logic; assignment operators, which do
the arithmetic operations and assign the value to another variable in one compact operation (operator); and the
conditional operator, also called a ternary operator, which assigns a value to a variable, based on the outcome of a
true or false (boolean) evaluation.
There are also the conceptually more advanced bitwise operators, used to perform operations at the binary data
(zeroes and ones) level, the logic of which is beyond the beginner scope of this book and the use of which is not as
common in Java game programming as these other, more mainstream types of operators, each of which you will be
using over the course of this book to accomplish various programming objectives in your game play logic.
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