PHP - String manipulation remove spcial characters and replace spaces

Question

I am getting strings from a database and then using the strings to build a URL. My issue is, some of the strings will have characters like < > & { } * general specia

Answer 1

str_replace(' ','-',$string);

alphanumeric:

$output = preg_replace("/[^A-Za-z0-9]/","",$input); 

if you want to keep the characters:

 htmlspecialchars($string);