How to find SPGroups where the user is a member using PowerShell

Question

How to find out a user who is part of the SPGroups in a site collection using PowerShell.I want to pass the userid and get the names of groups where he is part of.Later I want to delete his id from all these SPGroups.I wrote the below code, but am not getting success.

 $sitee= get-spsite "https://myDMS.mycompany.com"
 $webb= $sitee.Rootweb
 $inputusername ="in\userid"
 $Allgroups = $webb.SiteGroups
 foreach(singeGrp in $Allgroups)
  {
   SPUser muser = new-object SPUser
   foreach(SPuser suser in singeGrp.Users)                  
       {
           if(suser.Loginname -eq  muser.Loginname) 
            {
               singeGrp.Delete();
            }
       }
  }

Answer 1

You create the object muser, but never initialize it. So, your comparison is always false.

I would suggest inspecting the Groups property of the SPUser object. (The following is not tested since I don't have an environment handy.)

$site = get-spite "{siteUrl}"
$web = $site.RootWeb
$user = $web.AllUsers["{domain\\user_alias}"]
Foreach($group in $user.Groups) {
    $group.Users.Remove($user.LoginName)
}