in reply to hash map to give preference to 1st match

Using the name "value" for a key is confusing, try to change it to something else (float?).
Hash variable cannot be used with round brackets (%result()).
Are you sure you store the whole list of the URL's into your values (i.e. you use Hash of Arrays, HoA)? If yes, just use $result{$float}[0] to retrieve the first value. Do not you overwrite an older value with a new one when storing the values?