Java Reference
In-Depth Information
Example 3.1
Coercing a
byte
to
int
as if the
byte
were unsigned
byte c;
int ival;
...
ival = ((int) c) && 0xFF; // explicit cast needed
3.2.1.2
Java provides two different precisions of floating point numbers. They are:
Floating Point Types
•
float
: 32 bits
•
double
: 64 bits
The
float
type is not very useful at that precision, so
double
is much
more commonly seen. For other situations where precision is important, but
you can spare some cycles, consider the
BigDecimal
and
BigInteger
object classes.
Java floating point numbers are specified to follow the IEEE floating point
standard, IEEE 754.
3.2.1.3
Java also has a
boolean
type, along with constants
true
and
false
. In Java,
unlike C/C++,
boolean
values are a distinct type, and do not convert to
numeric types. For example, it is common in C to write:
Other Types
if (strlen(instr)) {
strcpy(buffer, instr);
}
In this case, the integer result of
strlen()
is used as a
boolean
, where
0
is
false
and any other value is
true
. This doesn't work in Java. The expression
must be of a
boolean
type.
Java also has a
char
type, which is
not
the same as a
byte
. The
char
is a
character, and in Java, characters are represented using Unicode (UTF-16).
They take two bytes each.
For more discussion on the differences between
byte
s and
char
s and
about Unicode, read the Java tutorial on the
java.sun.com
Web site or visit
www.unicode.org
, the international standard's Web site.
