Creates an SEO Friendly URL from a string

PHP SEO Friendly URL Function

// SEO Friendly Filter Function

function seoUrl($string) {

    $string = trim($string); // Trim String

    $string = strtolower($string); //Unwanted:  {UPPERCASE} ; / ? : @ & = + $ , . ! ~ * ' ( )

    $string = preg_replace("/[^a-z0-9_\s-]/", "", $string);  //Strip any unwanted characters

    $string = preg_replace("/[\s-]+/", " ", $string); // Clean multiple dashes or whitespaces

    $string = preg_replace("/[\s_]/", "-", $string); //Convert whitespaces and underscore to dash

    return $string;

}

another Solution using PHP's iconv with TRANSLIT:
https://blog.ueffing.net/post/2016/03/14/creating-seo-friendly-url/

Hmm there's a problem when words have accents, so I found this solution.