How to Trim the End of a Path in Javascript

I came across a situation recently where I needed to trim the end of a path in Javascript, and figured I’d share the quick, one-line solution, in case you need to do the same sometime.

Here’s the deal: I had a filepath that I needed to trim the filename off of, leaving just the path. So, I had this: /path/to/filename.jpg, and needed to trim that to /path/to.

The easiest way to do it? Use the lastIndexOf() method to find the last occurance of the slash, and trim from there, like this:

var string = '/path/to/filename.jpg'
var trimmedString = string.substr(0, string.lastIndexOf('/'));

console.log(trimmedString); // '/path/to'

Super easy. I’d considered using some variation of split('/'), but stumbled upon lastIndexOf(), which works much better. lastIndexOf() does just what it sounds like: gives you back the index of the last occurance of that character in the string. Using that inside of substr(), you can have it take the substring from the beginning, up to that indexed character. Piece of cake!

Hope this helps you if you need to trim the end of a path. Great for filepaths, and even for paths that might be in dot notation.

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