Question

Trying to remove duplicate array elements without using array_unique. I am trying to use the array_flip method but that doesn’t seem to be working for me. The Code that I have so far is:

$arr = array(
   'a' => "one",
   'b' => "two",
   'c' => "three",
   'd' => "two",
   'e' => "four",
   'f' => "five",
   'g' => "three",
   'h' => "two"
);

function removeDuplicates($arr) {


$arr = array_flip($arr);
$arr = array_flip($arr);

}
print_r(removeDuplicates($arr));

The output that I am trying to get ultimately is:

  [a] => one
    [e] => four
    [f] => five

This is just purely for educational purposes as I am trying to find different ways to do it. Any help is great appreciated.

Answer 1

Another solution would be:

$counts = array_count_values($arr);

foreach ($arr as $key => $value) {
        if ($counts[$value] > 1) {
                unset($arr[$key]);
        }
}

Also, array_unique makes sure there are no duplicate values, while you want the array without the values which had duplicates. That is quite different, I guess removing mention of the array_unique function will make the question less confusing.