JS:访问对象属性的两种方式区别之中括号引用方式

An advantage of bracket notation is that we are not restricted to just using strings in the brackets. We can also use variables whose values are property names:

var someObj = {propName: someValue};
var myProperty = "propName";
someObj[myProperty]

The last line is exactly the same as using

someObj["propName"]

.