php - Find a matching or closest value in an array

Question

How can I search and find, for a given target value, the closest value in an array?

Let's say I have this exemplary array:

array(0, 5, 10, 11, 12, 20)

For example, when I search with the target value 0, the function shall return 0; when I search with 3, it shall return 5; when I search with 14, it shall return 12.

Answer 1

Pass in the number you're searching for as the first parameter and the array of numbers to the second:

function getClosest($search, $arr) {
   $closest = null;
   foreach ($arr as $item) {
      if ($closest === null || abs($search - $closest) > abs($item - $search)) {
         $closest = $item;
      }
   }
   return $closest;
}