case-insensitive array_unique

Question

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?

Answer 1

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

Answer 2

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); } ?>