The following is an efficient, adaptable implementation of array_unique which always retains the first key having a given value:
<?php
function array_unique2(&$aray) {
$aHash = array();
foreach ($aray as $key => &$val) if (@$aHash[$val]++) unset ($aray[$key]);
}
?>
It is also adaptable to multi dimensional arrays. For example, if your array is a sequence of (multidimensional) points, then in place of @$aHash[$val]++ you could use @$aHash[implode("X",$val)]++
If you want to not have holes in your array, you can do an array_merge($aray) at the end.
Csaba Gabor
