Core Java - [Wrapper Class]

♠ Posted by Unknown in Core Java at 01:29

Wrapper Class

The vectors cannot handle primitive data types like int, float, long, char,  and double. Primitive data types may be converted into object types by using the wrapper classes contained in the java.lang package. Below table shows the simple data types and their corresponding wrapper class types.

Simple Type	Wrapper Class
boolean	Boolean
char	Character
double	Double
float	Float
int	Integer
long	Long

Converting Primitive to Objects Using Constructor	Converting Objects to Primitive using method	Converting Numbers to Strings	Converting String objects to Numeric objects	Converting Numeric Strings to Primitive Numbers
Integer IntVal = new Integer()	int i =  IntVal.intValue()	str = Integer.toString(i)	IntVal = Integer.valueOf()	int i = Integer.parseInt(str)
Float FloatVal = new Float()	float f = FloatVal.floatValue()	str = Float.toString(f)	FloatVal = Float.valueOf()	long l = Long.parseLong(str)
Double DoubleVal = new Double()	double d =  DoubleVal.doubleValue()	str = Double.toString(d)	DoubleVal = Double.valueOf()
Long LongVal = new Long()	long l = LongVal.longValue()	str = Long.toString(l)	LongVal = Long.valueOf()

The Wrapper classes have number of methods for handling primitive data types and objects.