how do i can restart NPM for Reactjs
<p>I'm rookie how to setup reactjs with NPM, after setting is working great when I see output said "hello world", by going to URL localhost:8080.</p>

<p>But this time I created more new folder move index.html and index.js to new folder, and I changed to "It works great" from "hello world" under new folder, but currently showing old output "hello world"</p>

<p>My question is that how can I re-run NPM after made changed webconfig.js and package.json! and the output should be showing under new folder file!</p>