问答题 import java.io.*;
public class abc
public static void main(String args[ ])
AB s = new AB("Hello!","I love JAVA.");
System.out.println(s.toString( ));


class AB
String s1;
String s2;
AB( String str1 , String str2 )
s1 = str1; s2 = str2;
public String toString( )
return s1+s2;