jquery / asp.net - get the number of images in a folder where the first two characters of the file name are XX

I have been looking for the best way to obtain the total number images in a folder where the first two characters on the file name are XX and place this number into a variable.

So for example - I have a folder containing the foll开发者_如何转开发owing images:

XX-01.jpg

XX-02.jpg

XX-03.jpg

YY-01.jpg

ZZ-01.jpg

So I would populate the variable with 3 in this case.

Does anyone know of any way to do this?

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Do not do it in jQuery.

Go server side instead. Those are the kind of bad code another developer will curse you for.