Counting occourences of a variable in an array filled with objects in JavaScript / Angular -

lets have array filled objects this:

 {conversation_id: 38   id: 99   is_seen: 1    message: "hej kristina"   timestamp: "2015-07-08t10:50:49.000z"'  }

now wish find out how many of these objects has value is_seen set 1 , conversation_id set 38.

i solve using foreach loop, looking solution cleaner , maybe more efficient.

my application angularjs application, i'm looking either native javascript or angular ways solve this.

you can use native array.filter() function:

var countofseenitems = my_array.filter(function (el) {   return el.conversation_id == 38 && is_seen == 1;  }).length;

JVParth