PHP Multi-Dimensional Array Remove Duplicate

How to remove duplicate values from a multi-dimensional array in PHP

Here is another way. No intermediate variables are saved.

We used this to de-duplicate results from a variety of overlapping queries.

$input = array_map("unserialize", array_unique(array_map("serialize", $input)));

php remove duplicates from multidimensional array by value

Thanks everyone, sometimes over-thinking can affect common sense.

I simply solved it from MYSQL query with something like:

 GROUP BY list_title ORDER BY list_date

PHP remove duplicate arrays inside a multi dimensional array

No function does this outright, you could use a combination of functions though. You could first sort all of sub batches of array first into ascending order first, then serialize each on them, utilize array_unique, then unserialize again to have that multi dimensional again:

foreach($arr as &$a){ sort($a); }
$arr = array_map('unserialize', array_unique(array_map('serialize', $arr)));
print_r($arr);

PHP remove duplicate values from multidimensional array

The user comments on the array_unique page do shed some light on this. You will most likely find some hidden gems in those comments - its a very handy documentation.

Just a quick browser through revealed the following to remove duplicates from a multi dimensional array:

<?php
function super_unique($array)
{
  $result = array_map("unserialize", array_unique(array_map("serialize", $array)));

  foreach ($result as $key => $value)
  {
    if ( is_array($value) )
    {
      $result[$key] = super_unique($value);
    }
  }

  return $result;
}
?>

php multi-dimensional array remove duplicate

A quick solution which uses the uniqueness of array indexes:

$newArr = array();
foreach ($array as $val) {
    $newArr[$val[2]] = $val;    
}
$array = array_values($newArr);

Notice 1: As visible from above, the last match for an email address is used instead of the first. This can be changed by replacing the second line with

foreach (array_reverse($array) as $val) {

Notice 2: The indexes in the resulting array are somewhat mixed up. But I guess this doesn't matter...

Remove duplicate values from a multidimensional array

I'll put this at the beginning, because I'd rather do this type of thing in the database if possible. You can change your query to get a result like the one you want.

SELECT name, MIN(id) FROM your_table GROUP BY name

If you need to do this in PHP for some other reason, here are a few different ways.

All of these involve assigning the row to your result array using the name as the key.

If you want to keep the first instance of each name, then as you iterate your input array, if a key matching the name of the row exists in the result array, don't add it. This way you'll end up with the first instance of the person's name in your result set.

foreach ($your_array as $person) {
    if (!isset($unique[$person['name']]) {
        $unique[$person['name']] = $person;
    }
}
$unique = array_values($unique);

If it doesn't matter which ID you get, then you can leave out the issetcheck. This way you'll end up with the last instance of each person's name in your result set because that key will be overwritten each time you encounter a duplicate.

foreach ($your_array as $person) {
    $unique[$person['name']] = $person;
}
$unique = array_values($unique);

If you need to keep all the ids associated with a name, append the id value to an array under the name key instead of adding the entire row.

foreach ($your_array as $person) {
    $people[$person['name']][] = $person['id];
}

This will give you a result like

['John' => ['D', 'U'], 'Grace' => ['K']];

Remove duplicates from multi dimentional array which include string and laravel collection

You can use Laravel's Collection::unique method:

$unique = collect($yourArray)->unique('email');

By passing in email into the method, you're telling Laravel to look at that specific field in your dataset, rather than the data as a whole. You can then convert it back to an array using toArray.

$unique = collect($yourArray)->unique('email')->toArray();

You can also pass a closure to the unique method to allow you to define the value that you want to compare for each object to determine uniqueness:

$unique = collect($yourArray)->unique(function ($item) {
    return $item['email'];
});