@barlop Ah damn, I completely forgot about the original idea behind static class variables, it ideally lends itself here. To make the code more visible you could basically make a method that has the array and the left and right indices of the array to be sorted as a parameter as well as the key that shall be used for it and in that method first change the static variable and then call sort. (Part1)

That would keep the code of the search algorithm more independent, as it then does not have to deal with the question what key needs to be used (since that question is dealt with beforehand). Coding 2 less methods is in general not a problem, but then the code in your search algorithm is still assuming more knowledge about the object the second you take the less method that allows you to retrieve your key of choice. The second option via static variable seems to be the best option.

Thanks a lot!

what? how do static vars work there?

that sounds horrific.