Underscore.js 1.7の使い方 Collections編 where

var r = document.getElementById("r");
var data = [
  { name: 'ito', age: 10, sex: 'Male' },
  { name: 'sato', age: 20, sex: 'Male' },
  { name: 'yamada', age: 20, sex: 'Female' },
  { name: 'suzuki', age: 30, sex: 'Female' }
];
var arr = _.where(data, {age: 20});
console.log(arr);
// =>  [Object { name="sato", age=20, sex="Male"}, Object { name="yamada", age=20, sex="Female"}]
r.innerHTML = arr[1].name;
// => 'yamada'