/**
* @name FixedArray
* @param array $Array
* @param string $ReturnDelimiter
* @param string $ReturnTyp
* @return mixed
*/
function FixedArray($Array, $ReturnDelimiter = '|', $ReturnTyp = 'Array') {
$ArrayChecked = array();
if ( $ReturnTyp == 'Array' ) { $Return = array(); } else { $Return = ''; }
foreach ( $Array as $String ) {
if ( false == in_array($String, $ArrayChecked) ) {
if ( $ReturnTyp == 'Array' ) {
$Return[] = $String;
} else {
$Return .= $String.$ReturnDelimiter;
}
$ArrayChecked[] = $String;
}
}
return $Return;
}

$Keys = FixedArray(array('a', 'b', 'a'));
print_r($Keys);