Do not define member variables as public

Class helloworld {<br/> Public static void main (string [] ARGs) {<br/> helloworld hW = new helloworld (); <br/> HW. printerror (); <br/>}< br/> void printerror () {<br/> variable v = new variable (); <br/> v. D = 123.0; // otherwise, the troublemakers that disrupt the Domain value may be found anywhere. <Br/> v. vaR (); <br/>}< br/> class variable {<br/> Public double D = 0; // do not define the member variables as Public <br/> void VAR () {<br/> system. out. println ("variable D is:" + d); <br/>}< br/>