1、往数据里添加json字符串

var arr = []
var json = {"name":"caocao","sex":"男"}
arr.push(json)
console.log(arr)

[{"name":"caocao","sex":"男"}]

2、往数组的json字符串里新增数据

var j =[{"name":"caocao","sex":"男"}];  
j[0].age='18'
console.log(j)

结果：

{name: "caocao", sex: "男", age: "18"}