Count Items in special folder by EcmaScript

Method 1: best practice for only counting items

function ViewAllFiles()
{
var context = new SP.ClientContext.get_current();
var web = context.get_web();
folder =web.getFolderByServerRelativeUrl(L_Menu_BaseUrl+'/Lists/{ListName}/5-2013');
context.load(folder);
context.executeQueryAsync(Function.createDelegate(this, this.success), Function.createDelegate(this, this.failed));
}
function success()
{
var numberCount = folder.get_itemCount();
alert(numberCount )
}
function failed()
{

alert("error");
}

Method 2: query all item in folder

function ViewAllFiles()

{

var context = new SP.ClientContext.get_current();

var web = context.get_web();

var list = web.get_lists().getByTitle('MenuTracking');

var query = '<View></View>';

var camlQuery = new SP.CamlQuery.createAllFoldersQuery();

camlQuery.set_viewXml(query);

camlQuery.set_folderServerRelativeUrl('Lists/{List Name}/5-2013');

allItems = list.getItems(camlQuery);

context.load(allItems);

context.executeQueryAsync(Function.createDelegate(this, this.success), Function.createDelegate(this, this.failed));

}

function success()

{

var numberCount = this.allItems.get_count();

alert(numberCount )

var ListEnumerator = this.allItems.getEnumerator();

 while (ListEnumerator.moveNext()) {

   var currentItem = ListEnumerator.get_current();

   var _contentType = currentItem.get_fileSystemObjectType();

   if(currentItem.get_fileSystemObjectType() == '1') {

        //FolderNames  += currentItem.get_item('Title')+ '\n';

   }

 }

}

function failed()

{

alert("error");

}