Question

I’m trying to add an item to a PHP array. The item I’m trying to add to the array may have the same index as an item which is already in the array. How can I add the item to the array without overwriting an item that shares the same index inside the array? I’d like similar indexes to turn into a 2D array.

//Original Array
$array = array (
            "item1" => "data1",
            "item2" => "data2",
            "item3" => "data3"
        );

//Add items to array
$array["item1"] = "data2d";
$array["item5"] = "data4";

//Desired output
array (
    "item1" => array("data1", "data4"),
    "item2" => "data2",
    "item3" => "data3",
    "item4" => "data4"
);

How would I achieve the desired output?

Answer 1

Try a function like below. The function has not been tested so there might be some syntax errors.

function addArray(&$array, $key, $value) {
  if (isset($array[$key])) {
    if (!is_array($array[$key])) {
      $tmp = $array[$key];
      $array[$key] = array($tmp, $value);
    }
    else {
      array_push($array[$key], $value);
    }
  }
  else {
    $array[$key] = $value;
  }      
}

Used like

$array = array (
  "item1" => "data1",
  "item2" => "data2",
  "item3" => "data3"
);

//Add items to array
addArray($array, 'item1', 'data2d');