Get extension file by path javascript

Get-extension-file-by-path-javascript.js

var path = "http://localhost/project/temp/folder/file.mp4";
var array = path.split('/'); // split / 
var ultimo = array.pop(); // get last index
var basename = ultimo.split('.'); // splt .
var extension = basename.pop(); // get last index
alert(extension);

// OR

var path ="http://localhost/project/temp/folder/file.mp4";
var array = path.split('.'); // splt .
extension = array[array.length -1 ]; // get last index
alert(extension);