You use one of the wrapper classes –Byte
,Double
,Float
,Integer
,Long
, orShort
– to wrap a number of primitive type in an object. The Java compiler automatically wraps (boxes) primitives for you when necessary and unboxes them, again when necessary.The
Number
classes include constants and useful class methods. TheMIN_VALUE
andMAX_VALUE
constants contain the smallest and largest values that can be contained by an object of that type. ThebyteValue
,shortValue
, and similar methods convert one numeric type to another. ThevalueOf
method converts a string to a number, and thetoString
method converts a number to a string.To format a string containing numbers for output, you can use the
printf()
orformat()
methods in thePrintStream
class. Alternatively, you can use theNumberFormat
class to customize numerical formats using patterns.The
Math
class contains a variety of class methods for performing mathematical functions, including exponential, logarithmic, and trigonometric methods.Math
also includes basic arithmetic functions, such as absolute value and rounding, and a method,random()
, for generating random numbers.