array-movement-functions

function down($array,$element) {
    if(count($array)-1 > $element) {
        $newArray = array_slice($array,0,$element,true);
        $newArray[] = $array[$element+1];
        $newArray[] = $array[$element];
        $newArray += array_slice(
            $array,
            $element+2,
            count($array),
            true
        );
        return($newArray);
    } else { 
        return $array; 
    }
}
  
function up($array,$element) {
    if( $element > 0 and $element < count($array) ) {
        $newArray = array_slice($array,0,($element-1),true);
        $newArray[] = $array[$element];
        $newArray[] = $array[$element-1];
        $newArray += array_slice(
            $array,
            ($element+1),
            count($array),
            true
        );
        return($newArray);
    } else {
        return $array;
    }
}