What potential issue arises when submitting an array with duplicate values in PHP?

Submitting an array with duplicate values in PHP can lead to unexpected behavior when processing the data, as duplicate values may interfere with the intended logic of the script. To solve this issue, you can remove duplicate values from the array before further processing it.

// Remove duplicate values from an array
$array = [1, 2, 2, 3, 4, 4, 5];
$array = array_unique($array);

// Now $array will contain unique values only
print_r($array);