function arrayUnique($array, $preserveKeys = false)  
{  
    // Unique Array for return  
    $arrayRewrite = array();  
    // Array with the md5 hashes  
    $arrayHashes = array();  
    foreach($array as $key => $item) {  
        // Serialize the current element and create a md5 hash  
        $hash = md5(serialize($item));  
        // If the md5 didn't come up yet, add the element to  
        // to arrayRewrite, otherwise drop it  
        if (!isset($arrayHashes[$hash])) {  
            // Save the current element hash  
            $arrayHashes[$hash] = $hash;  
            // Add element to the unique Array  
            if ($preserveKeys) {  
                $arrayRewrite[$key] = $item;  
            } else {  
                $arrayRewrite[] = $item;  
            }  
        }  
    }  
    return $arrayRewrite;  
}

Filter array to have only unique values

Filter array to have only unique values

PHP