mongodb - mongo db get collections starting with -

i have number of collections names like

app_users5473275725743 app_users5473275725746 app_users5473275725747 app_users5473275725748 

i want able find collections starting name 'app_users', while db.getcollectionnames returns collection names.

db.getcollectionnames().foreach(function(collname) {     if (collname.startswith("app_users")) {         print(collname);     } });