下面程序段的输出结果为 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='+Obj1.B) ; Test Obj2=new Test(); System.out.println('='+Obja+' b='+ObjB) ; } }