Slug Create Function in PHP. URL Rewriting According to SEO Rules

SEO friendly Slug is very important in Search Engine Optimization. It is used to rewrite your URL as your title.
as if you write title: "My Name Is Sami" And if it is a page. Then
Its URL will be :
www.QWC.me/?page=1 [1 Is Page ID]

If you use title in URL it can be like it
www.QWC.me/?page=my20%name20%is20%sami

But if you use slug function: URL will be SEO friendly like

www.QWC.me/?page=my-name-is-sami

There are many function: I am going to add 2 good functions for it. there is no any personal PHP built in function.

1:

 function slug($str, $replace=array(), $delimiter='-')  
      {  
           if( !empty($replace) )  
      {  
           $str = str_replace((array)$replace, ' ', $str);  
      }  
           $clean = iconv('UTF-8', 'ASCII//TRANSLIT', $str);  
           $clean = preg_replace("/[^a-zA-Z0-9\/_|+ -]/", '', $clean);  
           $clean = strtolower(trim($clean, '-'));  
           $clean = preg_replace("/[\/_|+ -]+/", $delimiter, $clean);  
           $clean = form_validation($clean);  
           return $clean;  
 }  

---

2:

 function slug2($string){  
   $slug=preg_replace('/[^A-Za-z0-9-]+/', '-', $string);  
   return $slug;  
 }