3下面的输出结果为( )。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 Obj 1 = new Test(12,45 ) System.out.println('a='+Obja+' b='+Objb) Test Obj2 = new Test() System.out.println('a='+Obja+' b='+Objb) }}