类MyDate定义如下： class MyDate{ int year=2019, month=5, day=30; { year=2017; month=1; day = 1; } MyDate(int year, int month, int day){this.year=year; this.month=month; this.day=day;} MyData(){this(2018,12,31);} }; 执行语句 MyDate adate=new MyDate(); adate.year、adate.month、adate.day的值为_____________。 A: 2019 5 30 B: 2017 1 1 C: 2018 12 31 D: 不确定不确定不确定

假设现在时间是2018-4-18 20:02:10 var mydate = new Date mydate.getMonth()的结果是