Question

this doesn’t work. When I enter html into the form. For instance when I enter a horizontal rule it displays in the echo output even though the $value was passed through strip_tags.

function sanitizeString($var){
   $var = strip_tags($var);
   $var = htmlentities($var);
   return stripslashes($var);
}

foreach($_POST as $key => $value){
   echo $key."<br>";
   sanitizeString($value);
   echo $value."<br>";
} 

Answer 1

You aren’t actually changing $value. You are throwing away the return value. Try $value = sanitizeString($value);.