What would be the most efficient way to sort and remove duplicate values in a multi-array in PHP?

To efficiently sort and remove duplicate values in a multi-array in PHP, you can use the combination of array_map, array_unique, and array_values functions. First, flatten the multi-array using array_map, then use array_unique to remove duplicates, and finally, reindex the array using array_values.

// Sample multi-array
$multiArray = array(
    array(1, 2, 3),
    array(4, 5, 6),
    array(1, 2, 3)
);

// Flatten the multi-array and remove duplicates
$flattenedArray = array_unique(array_merge(...$multiArray));

// Reindex the array
$uniqueValuesArray = array_values($flattenedArray);

print_r($uniqueValuesArray);