How to trim a file extension from a String in JavaScript?

Question

For example, assuming that x = filename.jpg, I want to get filename, where filename could be any file name (Let\'s assume the file nam

Answer 1

This is the code I use to remove the extension from a filename, without using either regex or indexOf (indexOf is not supported in IE8). It assumes that the extension is any text after the last '.' character.

It works for:

• files without an extension: "myletter"
• files with '.' in the name: "my.letter.txt"
• unknown length of file extension: "my.letter.html"

Here's the code:

var filename = "my.letter.txt" // some filename

var substrings = filename.split('.'); // split the string at '.'
if (substrings.length == 1)
{
  return filename; // there was no file extension, file was something like 'myfile'
}
else
{
  var ext = substrings.pop(); // remove the last element
  var name = substrings.join(""); // rejoin the remaining elements without separator
  name = ([name, ext]).join("."); // readd the extension
  return name;
}