How to use

b

function

in

Array

QUnit.test('`_.' + methodName + '` should perform a ' + (isDeep ? 'deep' : 'shallow') + ' clone when used as an iteratee for methods like `_.map`', function(assert) {
    assert.expect(2);

    var expected = [{ 'a': [0] }, { 'b': [1] }],
      actual = lodashStable.map(expected, func);

    assert.deepEqual(actual, expected);

    if (isDeep) {
     assert.ok(actual[0] !== expected[0] && actual[0].a !== expected[0].a && actual[1].b !== expected[1].b);
    } else {
     assert.ok(actual[0] !== expected[0] && actual[0].a === expected[0].a && actual[1].b === expected[1].b);
    }
   });

test('where', function() {
  var list = [{a: 1, b: 2}, {a: 2, b: 2}, {a: 1, b: 3}, {a: 1, b: 4}];
  var result = _.where(list, {a: 1});
  equal(result.length, 3);
  equal(result[result.length - 1].b, 4);
  result = _.where(list, {b: 2});
  equal(result.length, 2);
  equal(result[0].a, 1);

  result = _.where(list, {a: 1}, true);
  equal(result.b, 2, "Only get the first object matched.")
  result = _.where(list, {a: 1}, false);
  equal(result.length, 3);
 });