1 public class emptystring 2 { main(String[] args)3 public static void main(String[] args) 4 { 5 System.out.println("null".equals(n(0) + "")); 6 System.out.println("null".equals("" + n(0))); 7 System.out.println("x".equals(n(1) + "")); 8 System.out.println("x".equals("" + n(1))); 9 } 10 n(int i)11 static String n(int i) 12 { 13 if (i==0) return null; else return "x"; 14 } 15 } 16