Determine file extensions using JavaScript

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Heads up! This post was written in 2008, so it may contain information that is no longer accurate. I keep posts like this around for historical purposes and to prevent link rot, so please keep this in mind as you're reading.

— Cory

A quick JavaScript function to determine a file's extension.

function fileExt(path) {
  return path.substr(path.lastIndexOf('.') + 1);