JSFiddle - React, Tailwind, and code Playground

by neonDog

JavaScript

const insertAt = (str, sub, pos) => `${str.slice(0, pos)}${sub}${str.slice(pos)}`;

const img = 'https://i.imgur.com/12345.jpg';

if (img.startsWith('https://i.imgur.com/')) {
	console.log(insertAt(img, 'm', img.length -4));
}