PHP - Create Unique Array of Object by comparing one property

geohashes.json

[
  {
    "offer_nid": "16524",
    "offer_lm": "1610224798",
    "biz_nid": "73865",
    "biz_lm": "1602519728",
    "geo": "9xjhn",
    "counter": "1"
  },
  {
    "offer_nid": "16524",
    "offer_lm": "1610224798",
    "biz_nid": "81583",
    "biz_lm": "1605971711",
    "geo": "9xjhn",
    "counter": "2"
  },
  {
    "offer_nid": "82114",
    "offer_lm": "1610128855",
    "biz_nid": "73217",
    "biz_lm": "1601659864",
    "geo": "9xjhn",
    "counter": "3"
  },
  {
    "offer_nid": "82113",
    "offer_lm": "1610128855",
    "biz_nid": "73209",
    "biz_lm": "1601659864",
    "geo": "9xjqb",
    "counter": "4"
  },
]

unique_array_of_objects.php

// Let's imagine you have a JSON array:
$geohases = "./geohashes.json"
$jsonRequest = getJSON($geohases);
$jsonArray = json_decode($latestIndex);

// But you want to filter out objects you consider "duplicates" because of a duplicate property.
// First, make a unique array chosing one of the object properties:

function returnUniqueObjects($array, $property) {
  // Technically, this will consider objects unique by comparing only ONE of the objects' properties
  $tempArray = array_unique(array_column($array, $property));
  // With our temporary unique one-dimensional array, we have the indexes of unique objects. Let's use that index to retrieve matches:
  $onePropertyUniqueArrayOfObjects = array_values(array_intersect_key($array, $tempArray));
  return $onePropertyUniqueArrayOfObjects;
}

$unique = returnUniqueObjects($jsonArray, "geo");