只有最近才有ES6。他们称为计算属性名称

Only recently with ES6. They are called "computed property names"

从 MDN ：

从ECMAScript 2015开始，对象初始化器语法也是
支持计算的属性名称。这允许您在括号 [] 中放入一个表达式
，这将被计算为属性名称。

Starting with ECMAScript 2015, the object initializer syntax also supports computed property names. That allows you to put an expression in brackets [], that will be computed as the property name.