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

Fast and works correctly with paths

(filename.match(/[^\\\/]\.([^.\\\/]+)$/) || [null]).pop()

Some edge cases

/path/.htaccess => null
/dir.with.dot/file => null

Solutions using split are slow and solutions with lastIndexOf don't handle edge cases.