Changing order of characters in a string using JavaScript

Question

I'm catching the date from a form as a string and pass it to a API-Request-URL.

The date string is in this format: 16022019 But the API accepts a date string only in this format: 20190216.

Basically, in my string, I need to change the position of the first 2 characters with the position of the last 4 characters.

I fixed the issue as follow:

let date = e.target.elements.date.value; // 16022019

const dateFirst = date.slice(0, 2);
const dateMiddle = date.slice(2, 4);
const dateLast = date.slice(4, 8);
date = `${dateLast}${dateMiddle}${dateFirst}`; // 20190216

But I'm not sure if this is a good solution. Is there any better way to achieve the same result?

Answer 1

I don't see any problem with your method. in case you want to know alternate you can try this.

This uses regex to capture digits of desired width and than places to desired place.

let str = `16022019`
console.log(str.replace(/(\d{2})(\d{2})(\d{4})/,"$3$2$1"))