remove duplicates from comma separated string

Question

Is there a better (faster) solution to remove duplicates from a comma separated string?

public function d($dep) { 
    if (strpos($dep,\',\') !== false) {
           


        

Answer 1

You could use the uniqueness of array keys:

function d($dep) {
    return implode(',', array_keys(array_flip(explode(',', $dep))));
}

array_flip swaps the key-value association, so the values become the keys and vice versa. This will automatically eliminate duplicates. Its runtime complexity is O(n).