apex:variable

1<!-- For this example to render properly, you must associate the Visualforce page 
2with a valid contact record in the URL. 
3For example, if 001D000000IRt53 is the contact ID, the resulting URL should be: 
4https://MyDomain_login_URL/apex/myPage?id=001D000000IRt53
5See the Visualforce Developer's Guide Quick Start Tutorial for more information. -->
6         
7<!-- Page: -->
8<apex:page controller="variableCon">
9    <apex:variable var="c" value="{!contact}" />
10        
11    <p>Greetings, {!c.LastName}.</p>
12</apex:page>
13
14/*** Controller ***/
15public class variableCon {
16    Contact contact;
17
18    public Contact getContact() {
19        if (contact == null){                      
20        contact = [select LastName from Contact where 
21            id = :ApexPages.currentPage().getParameters().get('id')];
22        }
23        return contact;
24    }
25}