Unexpected token o in JSON at position 1, JSON parsing problem

Follow the video to log in , All of a sudden, an error was reported Unexpected token o in JSON at position 1

It seems that there should be an error in parsing , But here I use all kinds of console.log debugging , I can't find the problem
from cookie Get the user information and assign it to the object , Let's see what's given ：


There should be something wrong here , There should be a problem when depositing , Wrong format

When saving, the object is directly saved , It's not a string , hinder parse The parsing method is to parse the string into json object , So when saving , You should first convert the object to a string ： cookie.set('guli_ucenter', JSON.stringify(this.loginInfo), { domain: 'localhost' })
It is very nice：

Here is JSON.parse() and JSON.stringify() usage ：

JSON.parse() Used to parse... From a string json object , Such as ：

var str = '{"name":"LeonWu","age":"18"}'
JSON.parse(str);
// The result is a Object
// age: "18";
// name: "LeonWu";

JSON.stringify() Used to parse a string from an object , Such as

var a = {
    a:1,b:2,c:"LeonWu"};
JSON.stringify(a);
// The result is  "{"a":1,"b":2,"c":"LeonWu"}"

Reasons for reporting errors ： The data to be converted is originally object, This method parses a string into json object , If you convert again, you will report an error ;

Because of the Object Pass as a parameter to JSON.parse() In time , It will silently Object To string,
Will call the on the prototype first toString() Method ; The result is ”[object Object]”,JSON.parse Will be the first character ’[‘ Understood as the beginning of the array , Second character ’o’ I don't know how to deal with ; So the above error message is thrown Unexpected token o in JSON at position 1.

Reference link ：
Unexpected token o in JSON at position 1 The reason for the error