How can I get file extensions with JavaScript?

Question

See code:

var file1 = \"50.xsl\";
var file2 = \"30.doc\";
getFileExtension(file1); //returns xsl
getFileExtension(file2); //returns doc

function getFileExt         


        

Answer 1

There is a standard library function for this in the path module:

import path from 'path';

console.log(path.extname('abc.txt'));

Output:

.txt

So, if you only want the format:

path.extname('abc.txt').slice(1) // 'txt'

If there is no extension, then the function will return an empty string:

path.extname('abc') // ''

If you are using Node, then path is built-in. If you are targetting the browser, then Webpack will bundle a path implementation for you. If you are targetting the browser without Webpack, then you can include path-browserify manually.

There is no reason to do string splitting or regex.