remove_duplicate_from_object_array.js

// object array
var ary = [
  ['aaa', 1],
  ['bbb', 2],
  ['ccc', 3],
  ['ddd', 4],
  ['eee', 5],
  ['ddd', 4],
  ['bbb', 2],
  ['aaa', 1],
];

var values = [];
var no_overlapped = ary.filter(function(e) {
  if (values.indexOf(e[0]) === -1) {
    values.push(e[0]);
    return e;
  }
});

console.log(no_overlapped);