可以在外面动态的设置key值

var data = {};
data['key1'] = "哈哈哈";
var variable = 'key2';
data[variable] = "嘿嘿嘿";
data.key3 = "也行";

 
console.log(data);  //{key1: "哈哈哈",key2: "嘿嘿嘿",key3: "也行"}

可以写js表达式

const a={name:'xxx',age:100}
a[9>10?'name':'age']