1. 常规用法

let data = [{name:"Tom",sex:1,age:20},{name:"Lily",sex:0,age:21}]
//将JavaScript对象转换为JSON格式的字符串
let result = JSON.stringify(data)
console.log(result)
//[{"name":"Tom","sex":1,"age":20},{"name":"Lily","sex":0,"age":21}]

2. 数据的提取

let result = JSON.stringify(data,["name","age"])
console.log(result)
//[{"name":"Tom","age":20},{"name":"Lily","age":21}]

3. 数据的修改

let result = JSON.stringify(data,function (key, value) {
    if(key==="sex"){
        return ["女生","男生"][value];
    }
    return value;
});
//[{"name":"Tom","sex":"男生","age":20},{"name":"Lily","sex":"女生","age":21}]