Check If current User member of Sharepoint Group using JSOM (2013 or 2010)

The following block of code will help you identify if the current logged in user is already a part of any SharePoint group .


Say for example, I need to check if the current user belongs to Elninos Football Team SharePoint group .  You can use the following scripts in script web parts, content editor web parts, or visual web parts.


Please see the code below:

<script>

// Provide the Group name

var grpName="Elninos Football Team";
$(document).ready(function() {

 ExecuteOrDelayUntilScriptLoaded(IsCurrentUserMemberOfGroup, "sp.js");

 
});
     
  });
//Ready function ends

function IsCurrentUserMemberOfGroup()
{

       
        var userInGroup;
        var currentContext = new SP.ClientContext.get_current();
        var currentWeb = currentContext.get_web();    
        var currentUser = currentContext.get_web().get_currentUser();
        currentContext.load(currentUser);
        var allGroups = currentWeb.get_siteGroups();
        currentContext.load(allGroups);
        currentContext.load(allGroups, 'Include(Users)');
        currentContext.executeQueryAsync(OnSuccess,OnFailure);
       
  
        function OnSuccess(sender, args) {

            var userInGroup = false;

          
            var groupEnumerator = allGroups.getEnumerator();
            while (groupEnumerator.moveNext() && !userInGroup)
            {
               var oGroup = groupEnumerator.get_current();
               if (oGroup.get_title() ==  grpName )
               {
                  var collUser = oGroup.get_users();
                  var userEnumerator = collUser.getEnumerator();
                  while (userEnumerator.moveNext() && !userInGroup)

        {
                  var oUser = userEnumerator.get_current();
                  if (oUser.get_id() == currentUser.get_id())
                   {
                    userInGroup = true;
                    alert("User is a member of the Group you have given");
                   }
                   }
                }
            }
       }

        function OnFailure(sender, args) {
  alert("User not found");
        }      
}

</script>