Creates an array of elements split into two groups, the first of which contains elements predicate returns truthy for, while the second of which contains elements predicate returns falsey for. The predicate is invoked with three arguments: (value, index|key, collection).

var resolve = function(result) {
  return _.map(result, function(array) { return _.map(array, 'user'); });
};

var users = [
  { 'user': 'barney',  'age': 36, 'active': false },
  { 'user': 'fred',    'age': 40, 'active': true },
  { 'user': 'pebbles', 'age': 1,  'active': false }
];

resolve( _.partition(users, function(o) { return o.active; }) );
// => [['fred'], ['barney', 'pebbles']]

// using the `_.matches` callback shorthand
resolve( _.partition(users, { 'age': 1, 'active': false }) );
// => [['pebbles'], ['barney', 'fred']]

// using the `_.matchesProperty` callback shorthand
resolve( _.partition(users, ['active', false]) );
// => [['barney', 'pebbles'], ['fred']]

// using the `_.property` callback shorthand
resolve( _.partition(users, 'active') );
// => [['fred'], ['barney', 'pebbles']]