Visual Upgrade in 2010 , On all sites in a web application

Upgrade all the sites in a web application in SharePoint 2010 . You can Use this SharePoint PowerShell code to accomplish

$SPwebApp = Get-SPWebApplication "http://SP2010.com"
 
    foreach ($SPsite in $SPwebApp.Sites)
    {
       foreach($SPweb in $SPsite.AllWebs)
        {
         
           $SPweb.UIVersion = 4
       $SPweb.Update()
    write-host $spweb.url
        }
    }
read-host  #just to pause