Retrieve all user in SharePoint 2010 site using Javascript client object model

To List out all the users in a site or web an easy way is to access the User Information list of the current site or web.

Here is a short example of how to get it

function GetAllUsers()
{
var clientContext = new SP.ClientContext.get_current();

var web = clientContext.get_web();

var userInfoList = web.get_siteUserInfoList();

var camlQuery = new SP.CamlQuery();

camlQuery.set_viewXml(‘’ +’’ + userID + ‘’ +

‘1’);

this.collListItem = userInfoList.getItems(camlQuery);

clientContext.load(collListItem);

clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded),Function.createDelegate(this, this.onQueryFailed));
}

function onQuerySucceeded(sender, args)
{

var item = collListItem.itemAt(0);

var profileNotes = item.get_item(‘Notes’);
alert(profileNotes);
}
function onQueryFailed(sender, args)
{
}
}