var a={"id":1,"name":"danlis"};
//添加属性
a.age=18;
console.log(a);
//结果：Object { id: 1, name: "danlis", age: 18 }
//修改属性
a.age="我怎么知道";
//结果：Object { id: 1, name: "danlis", age: "我怎么知道" }
//删除属性
delete a.age;
//结果：Object { id: 1, name: "danlis" }
原文：https://www.cnblogs.com/guoliping/p/9957141.html