php - Picking the nearest value from an array reflecting ranges

Question

I have an array that reflects rebate percentages depending on the number of items ordered:

$rebates = array(
   1 => 0,
   3 => 10,
   5 => 25,
  10 => 35)

meaning that for one or two items, you get no rebate; for 3+ items you get 10%, for 5+ items 20%, for 10+ 35% and so on.

Is there an elegant, one-line way to get the correct rebate percentage for an arbitrary number of items, say 7?

Obviously, this can be solved using a simple loop: That's not what I'm looking for. I'm interested whether there is a core array or other function that I don't know of that can do this more elegantly.

I'm going to award the accepted answer a bounty of 200, but apparently, I have to wait 24 hours until I can do that. The question is solved.

Answer 1

Here's another one, again not short at all.

$percent = $rebates[max(array_intersect(array_keys($rebates),range(0,$items)))];

The idea is basically to get the highest key (max) which is somewhere between 0 and $items.