How to get file extensions using JavaScript ?

To extract file extensions using JavaScript, there are several effective methods such as:

Using split() and pop() method:

This method breaks the filename into two parts: the name and the extension. The extension is then retrieved by popping the last element of the array.

Example :

let fileName = 'document.txt';
let extension = fileName.split('.').pop(); // Returns 'txt'

Using substring() and lastIndexOf() method:

The substring method fetches a portion of the string starting from the index found by the lastIndexOf() method, which locates the period(.) in the filename.
Example:

let fileName = 'document.txt';
let extension = fileName.substring(fileName.lastIndexOf('.') + 1); // Returns 'txt'

Using match() method with Regular Expression:

This method uses a regular expression to find and extract the file extension. It matches everything after the period(.) in the filename.
Example :

let fileName = 'document.txt';
let regex = /[^.]+$/;
let extension = fileName.match(regex); // Returns 'txt'

We have various method to get the file extension.

Keep Learning 🙂