var _ =require('underscore');var users =[{'id':1,'name':'Sam','last':'Brown'},{'id':2,'name':'Joe','last':'Black'},{'id':3,'name':'Julie','last':'Jordon'},{'id':4,'name':'Tim','last':'Jane'}];// Get index of first user whose id is evenvar result = _.findKey(users,function(user){return user.id %2==0});
console.log(result);