JS如何将变量作为一个对象的Key

https://www.cnblogs.com/wangweizhang/p/10643404.html 转自

var lastWord = 'last word';

var a = {
  'first word': 'hello',
  [lastWord]: 'world'
};

a['first word'] // "hello"
a[lastWord] // "world"
a['last word'] // "world"