javascript get file extension from string

JavaScript
var ext =  fileName.split('.').pop();var ext = fileName.substr(fileName.lastIndexOf('.') + 1);// Use the lastIndexOf method to find the last period in the string, and get the part of the string after that:

var ext = fileName.substr(fileName.lastIndexOf('.') + 1);
var fileName = "myDocument.pdf";
var fileExtension = fileName.split('.').pop(); //"pdf"
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