How can I eliminate repeated elements but leaving the last element in the array PHP

Well, I need to be able to eliminate the repeated elements but keeping the last element, that is, eliminate the previous ones and leave the last one.

This is what I have

exists: [
 0: {intervention_id: 2, exists: "yes"}
 1: {intervention_id: 2, exists: "no"}
 2: {intervention_id: 2, exists: "yes"}
 3: {intervention_id: 5, exists: "yes"}
 4: {intervention_id: 6, exists: "no"}
 5: {intervention_id: 12, exists: "yes"}
]

I have to delete the previous ones.

0: {intervention_id: 2, exists: "yes"}
1: {intervention_id: 2, exists: "no"}

and leave this

2: {intervention_id: 2, exists: "yes"}

And this is what I need

exists: [
 0: {intervention_id: 2, exists: "yes"}
 1: {intervention_id: 5, exists: "yes"}
 2: {intervention_id: 6, exists: "no"}
 3: {intervention_id: 12, exists: "yes"}
]

I need to keep the last one and delete the previous ones

Try this but delete the last one not the previous ones.

function unique_multidim_array($array, $key) {
    $temp_array = array();
    $i = 0;
    $key_array = array();
   
    foreach($array as $val) {
        if (!in_array($val[$key], $key_array)) {
            $key_array[$i] = $val[$key];
            $temp_array[$i] = $val;
        }
        $i++;
    }
    return $temp_array;
}

You could simply override the value of the current element using the same key. In this case, you will always get the last element for each ID

function unique_multidim_array($array, $key) {
    $uniq = [];
    foreach($array as $val) {
        $curVal = $val[$key]; // shortcut of the value
        $uniq[$curVal] = $val; // override previous value if exists
    }
    return array_values($uniq); // array_values to re-index array
}

$exists = [
    ['intervention_id' => 2, 'exists' => 'yes'],
    ['intervention_id' => 2, 'exists' => 'no'],
    ['intervention_id' => 2, 'exists' => 'yes'],
    ['intervention_id' => 5, 'exists' => 'yes'],
    ['intervention_id' => 6, 'exists' => 'no'],
    ['intervention_id' => 12, 'exists' => 'yes'],
];
$uniq = unique_multidim_array($exists, 'intervention_id');
print_r($uniq);

Output:

Array(
    [0] => Array(
            [intervention_id] => 2
            [exists] => yes
        )
    [1] => Array(
            [intervention_id] => 5
            [exists] => yes
        )
    [2] => Array(
            [intervention_id] => 6
            [exists] => no
        )
    [3] => Array(
            [intervention_id] => 12
            [exists] => yes
        )
)

live demo

$data = [
    [ 'intervention_id' => 2, 'exists' => 'yes' ],
    [ 'intervention_id' => 2, 'exists' => 'no' ],
    [ 'intervention_id' => 2, 'exists' => 'yes' ],
    [ 'intervention_id' => 5, 'exists' => 'yes' ],
    [ 'intervention_id' => 6, 'exists' => 'no' ],
    [ 'intervention_id' => 12, 'exists' => 'yes' ]
];

$map = array_column($data, 'exists', 'intervention_id');

array_walk($map, function (&$value, $key) {
  $value = [ 'intervention_id' => $key, 'exists' => $value ];
}, ARRAY_FILTER_USE_BOTH);

$result = array_values($map);

print_r($result);