Other Java Operators - JAVA Programming for Engineers - page 74

derbitsofanoperandyouXORwithamaskinwhichthesebitsareset.If
theremainingbitsareclearinthemask,thentheoriginalvalueofthese
bitswillbepreservedintheresult,asisshownin Figure8-5 .

The ~ operator
The~operatorinvertsallbitsofasingleoperand.Inotherwords,itcon-
vertsall1-bitsto0andall0-bitsto1.Thisactioncorrespondstotheboolean
NOTfunction,asshownin Table8-3 . Figure8-5 showstheresultofaNOT
operation.

bitwise NOT 0101 0011 operand

1010 1100 result

Figure8-6ActionoftheNOTOperator

The <, >, and >> operators
TheJavashiftleft(<)andshiftright(>and>>)operatorsareusedtomove
operandbitstotherightortotheleft.Allthreeoperatorsrequireavalue
thatspecifiesthenumberofbitstobeshifted.Thefollowingexpression
shiftsleft,by2bitpositions,allthebitsinthevariablebitPattern:

int bitPattern = 127;
bitPattern = bitPattern < 2;

Theactionofaleftshiftbya1-bitpositioncanbeseenin Figure8-7 .

10101100

OPERAND BEFORE << 1

discarded

01011000

OPERAND AFTER << 1

0shiftedin

Figure8-7Actionofthe<Operator

Theoperationoftheleft-shift,asshownin Figure8-7 , determinesthat
the most significant bit is discarded. This could spell trouble when the op-