why dot env and not just other file? code example

Example 1: nodejs dotenv path how to set

// when yours .env is in other place then default, you can set path to it

const path = require('path')
require('dotenv').config({ path: path.resolve(__dirname, '../../.env') }); //use as many '../' as you need

Example 2: .env file vars nto defined in child directory

const ck = require('ckey');

const userName = ck.USER;     // [email protected]
const password = ck.PASSWORD; // iampassword123
const apiKey   = ck.API_KEY;  // 1234567890