Friday, March 11, 2005

Type Wrappers

Introduction

A type wrapper is an object that contains an instance variable of the corresponding primitive type. The type wrapper also provide constants and methods useful when dealing with the corresponding primitive type.

Discussion

Corresponding Type Wrappers
Primitive Type Type Wrapper
boolean Boolean
char Character
byte Byte
short Short
int Integer
long Long
float Float
double Double

There are also several wrappers without a corresponding primitive type.

Wrapper Group Type Bits Example
Void Void void n/a n/a
Number Superclass n/a n/a Number n = new Byte((byte) 15);
BigInteger Integer n/a arbitrary-precision java.math.BigInteger bi = java.math.BigInteger.ONE;
BigDecimal Floating-point n/a arbitrary-precision java.math.BigDecimal bd = new java.math.BigDecimal(3.14);

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