How to array_push unique values inside another array

Question

I have two arrays:

$DocumentID = array(document-1, document-2, document-3, document-4,
                    document-5, document-4, document-3, document-2);

$UniqueDocumentID = array();

I want to push the unique objects inside of $documentid array to $UniqueDocumentID array.

I can't use array_unique() as it copies the key of its predecessor array and I want sequential keys inside the $UniqueDocumentID array.

Answer 1

You could foreach() through $DocumentID and check for the current value in $UniqueDocumentID with in_array() and if not present add it. Or use the proper tool:

$UniqueDocumentID = array_unique($DocumentID);

To your comment about wanting sequential keys:

$UniqueDocumentID = array_values(array_unique($DocumentID));

The long way around:

$UniqueDocumentID = array();

foreach($DocumentID as $value) {
    if(!in_array($value, $UniqueDocumentID)) {
        $UniqueDocumentID[] = $value;
    }
}