Convert SteamID3 to SteamID64 - Javascript

gistfile1.txt

// Convert SteamID3 to SteamID64
// Use big js for precision with big numbers
const Big = require('big.js');

/*
 * Example: '[U:1:927695233]' -> '76561198887960961'
 * https://www.steamidfinder.com/lookup/U%3A1%3A927695233/
 */
function convertSteamId3ToSteamId64(steamId3) {
  const accountId = steamId3.replace('[', '').replace(']', '').split(':')[2];

  // 76561197960265728 is Valve's magic constant
  return Big(accountId).plus('76561197960265728').toString();
}