Regex to accept any 3 combinations is must but no space : I wanted to allow regex to accept minimum of 8 characters and any 3 combinations out of following 4 categories.

 1. One uppercase alpha character
 2. One lowercase alpha character
 3. One numeric character
 4. One special character

The good thing is, there are many regex available for my requirement but most of them allows **space**. I got this [Regex][1] from 
[here][2]. I tried to modify this in several ways but I couldn't succeed in writing a proper regex to validate a space along with 3 combinations as i mentioned above.


  [1]: https://regex101.com/r/vB7eF3/6
  [2]: http://stackoverflow.com/questions/5950756/regex-for-checking-that-at-least-3-of-4-different-character-groups-exist