In underscore, I can successfully find an item with a specific key value
var tv = [{id:1},{id:2}]
var voteID = 2;
var data = _.find(tv, function(voteItem){ r
findIndex was added in 1.8:
index = _.findIndex(tv, function(voteItem) { return voteItem.id == voteID })
See: http://underscorejs.org/#findIndex
Alternatively, this also works, if you don't mind making another temporary list:
index = _.indexOf(_.pluck(tv, 'id'), voteId);
See: http://underscorejs.org/#pluck