In the past, to create a public class field we would have used this syntax, instantiating the field in the constructor:

过去，要创建一个公共类字段，我们将使用以下语法，在构造函数中实例化该字段：

class Counter {  constructor() {    this.count = 0  }}

The new , which you can use since Chrome 72 and Node 12, allows us to use this syntax:

从Chrome 72和Node 12开始可以使用的新 ，使我们可以使用以下语法：

class Counter {  count = 0}

Much simpler!

简单得多！

翻译自: