Name
Double
Synopsis
This class
provides an immutable object wrapper around the
double
primitive data type. doubleValue(
)
returns the primitive double
value of
a Double
object, and there are other methods
(which override Number
methods and whose names all
end in “Value”) for returning a the
wrapped double
value as a variety of other
primitive types.
This class also provides some useful constants and static methods for
testing double
values.
MIN_VALUE
and MAX_VALUE
are the
smallest (closest to zero) and largest representable
double
values.
POSITIVE_INFINITY
and
NEGATIVE_INFINITY
are the
double
representations of
infinity and negative infinity, and
NaN
is special double
“not a number” value.
isInfinite( )
in class and instance method forms
tests whether a double
or a
Double
has an infinite value. Similarly,
isNaN( )
tests whether a double
or Double
is not-a-number; this is a comparison
that cannot be done directly because the NaN
constant never tests equal to any other value, including itself.
The static parseDouble(
)
method converts a
String
to a double
. The static
valueOf( )
converts a
String
to a Double
, and is
basically equivalent to the Double( )
constructor
that takes a String
argument. The static and
instance toString( )
methods perform the opposite
conversion: they convert a double
or a
Double
to a String
. See also
java.text.NumberFormat
for more flexible number
parsing and formatting.
The compareTo( )
method
makes Double
object Comparable
which is useful for ordering ...
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