Get indexes of 3 largest values in a flat array

I have an array in PHP which holds a bunch of unix timestamps.

As a simplified example, here is an array of 10 values.

$array = [
  1510790277,
  1586522582,
  1572272336,
  1650049585,
  1591332330,
  1698088238,
  1646561226,
  1639050043,
  1652067570,
  1548161804,
];

I need to produce an array containing the indexes of the 3 largest numbers in that array.

From the sample array, I would expect a result of [5, 8, 3] -- in that order.

Solution

You could use asort to sort the array and maintain index and then use slice along with the 4th parameter, again to maintain the index, to grap the top x number of elements you are after, and finally use array_keys.

There may well be a quicker way, but it's just to show there are plenty of PHP array functions to help you achieve the effect you're looking for.