check to see if a string contains sudden elements

["Reinhart Viane" <rv@xxxxxxxx>]

I have a page which gets the id of a user from the url.

$_GET[id]

 

Now this id can have two forms:

Normal: page.php?id=1

Not so normal: page.php?id=whatever|1

 

I can explode the second string so I only have the number (1). Explode ("|",
$_GET(id))

But this command fails my query in case we have a normal value

 

Is there a way to check the $_GET(id) to see if there is a | in it and in
that case explode it?

 

Thx in advance.

Reinhart