Convert a string of an array to an array js

Question

Why cant i convert this arr

let stringarr = "[2022年07月12日, 2022年08月09日]"

to this arr

let arr = JSON.parse(stringarr) ---> error

Unexpected token / in JSON at position 5

• Barmar: You need quotes around the dates.
• mouchin777: @Barmar what if i dont have them. what can i do then to convert it to an array
• Barmar: Write your own parser, there's nothing built-in for this.
• evolutionxbox: Fix the source of that data. It'll likely be much easier than writing a parser
• mouchin777: Adding quotes wont work either tho let stringarr = "['2022/07/12', '2022/08/09']" let arr = JSON.parse(stringarr) error

Answer 1

It's not valid JSON, since the array elements aren't quoted.

If the array elements are all dates formatted like that, you could use a regular expression to extract them.

let stringarr = "[2022年07月12日, 2022年08月09日]"
let dates = stringarr.match(/\d{4}\/\d{2}\/\d{2}/g);
console.log(dates);

Answer 2

what can i do then to convert it to an array

There are several ways to do that, if the format of the string stays like this. Here's an idea.

console.log(`[2022年07月12日, 2022年08月09日]`
 .slice(1, -1)
 .split(`, `));

Or edit to create a valid JSON string:

const dateArray = JSON.parse(
 `[2022年07月12日, 2022年08月09日]`
 .replace(/\[/, `["`)
 .replace(/\]/, `"]`)
 .replace(/, /g, `", "`));
 
console.log(dateArray);

Or indeed use the match method @Barmar supplied.

Answer 3

const regexp = /\d+\/\d+\/\d+/g;
const stringarr = "[2022年07月12日, 2022年08月09日]";
const arr = [...stringarr.matchAll(regexp)];
console.log(arr)

Answer 4

It's to much simple 😄.

As your input is a valid array in string format. So, remove [ ] brackets and split with comma (,). Then it automatically generates an array.

let stringarr = "[2022年07月12日, 2022年08月09日]";
let arr = stringarr.replace(/(\[|\])/g, '').split(',');

Output:

['2022/07/12', ' 2022年08月09日']