Q:

case-insensitive array_unique

I'm trying to write a few lines of code to make a case insensitive array unique type function. Here's what I have so far:
foreach ($topics as $value) {
    $lvalue = strtolower($value);
    $uvalue = strtolower($value);

    if (in_array($value, $topics) == FALSE || in_array($lvalue, $topics) == FALSE || in_array($uvalue, $topics) == FALSE) {
        array_push($utopics, $value);
    }
}

The trouble is the if statement. I think there's something wrong with my syntax, but I'm relatively new to PHP and I'm not sure what it is. Any help?

A:

function array_iunique( $array ) {
    return array_intersect_key(
        $array,
        array_unique( array_map( "strtolower", $array ) )
    );
}

A:

You're setting both lvalue and uvalue to the lower case version.
 $uvalue = strtolower($value);

should be
 $uvalue = strtoupper($value);

That said, this might be a little faster.  The performance of your function will degrade exponentially, while this will be more or less linear (at a guess, not a comp-sci major...)
<?php

function array_iunique($ar) {
  $uniq = array();
  foreach ($ar as $value)
    $uniq[strtolower($value)] = $value;
  return array_values($uniq);
}
?>

