codeigniter display warning error if argument in URL not provided - url

Question

If I don't provide the value in the URL for Codeigniter, it'll display a PHP Error was encountered saying it's missing argument for a function call. I do NOT want it displayed at all. If there's no argument in the URL, it should just reroute to its index function. How do I prevent that from happening?
For example, www.example.com/profile/id/45
anyone would guess and enter like this "www.example.com/profile/id"
that would generate the error. How do I prevent that? I tried, "if (!isset($id))" but it generated error before it reached to that condition.

Answer 1

just learned that the solution is simple:
function id($id=NULL)
{
if ($id===NULL)
{
redirect....
}
}

Answer 2

you can also use:
$this->uri->segment(2); // gets 'id'
$this->uri->segment(3); // gets '45'
then do a redirect, check out:
http://codeigniter.com/user_guide/helpers/url_helper.html

Answer 3

use default values for your function
function id($id=0){
if(there any record with $id being provided){
//do something
}else{
//id not provided,set to default values 0 and then
show_404();
}
}
no way there could be id = 0 so its automatically showerror without redirect, if user enter the url www.example.com/profile/id ,