json是一种数据结构 key:vaule
var cheng ={
"name":"zhangsan",
"age":18,
"sex":"男",
"like":true
}
js中json的键的双引号可以省略
var li={
name:"lisi",
age:17,
}
添加属性
li.sex="女";
console.log(cheng,li)