测验:查看JavaScript对象方向 ??? 查看JavaScript对象方向 ?: class Tree { constructor ( type ) { this . type = type ; } } 我们将如何创建上述class的实例? () Tree.initialize('Oak') (X) new Tree('Oak') () new Tree().constructor('Oak') () let oak = new Tree(); Tree.type = 'Oak' let oak = new Tree(); Tree.type = 'Oak' ?: