Java in a Nutshell, 5th Edition

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 ...