有如下程序 public class Test { int a,b; Test ( ) { a = 100; b = 200; } Test(int x, int y) { a = x; b = y; } public static void main(String args[]) { Test Obj1 = new Test(12,45); System.out.println("a = "Obj1.a+" b = "+Ob31.B) ; Test Obj1 = new Test(); System.out.println("a = "Obj1.a+" b = "+Obj1.B) ; } } 程序的运行结果为( )。