下列程序的输出结果为：                    
public class Example{       String str=new String("good");       char[]ch={'a','b','c'};       public static void main(String args[])      {            Example ex=new Example();            ex.change(ex.str,ex.ch);            System.out.print(ex.str+" and ");            System.out.print(ex.ch);       }       public void change(String str,char ch[])      {           str="test ok";           ch[0]='g';       } }