1  var arrayMap = require('./_arrayMap'),
 2      baseIntersection = require('./_baseIntersection'),
 3      baseIteratee = require('./_baseIteratee'),
 4      baseRest = require('./_baseRest'),
 5      castArrayLikeObject = require('./_castArrayLikeObject'),
 6      last = require('./last');
 7  
 8  /**
 9   * This method is like `_.intersection` except that it accepts `iteratee`
10   * which is invoked for each element of each `arrays` to generate the criterion
11   * by which they're compared. The order and references of result values are
12   * determined by the first array. The iteratee is invoked with one argument:
13   * (value).
14   *
15   * @static
16   * @memberOf _
17   * @since 4.0.0
18   * @category Array
19   * @param {...Array} [arrays] The arrays to inspect.
20   * @param {Function} [iteratee=_.identity] The iteratee invoked per element.
21   * @returns {Array} Returns the new array of intersecting values.
22   * @example
23   *
24   * _.intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor);
25   * // => [2.1]
26   *
27   * // The `_.property` iteratee shorthand.
28   * _.intersectionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
29   * // => [{ 'x': 1 }]
30   */
31  var intersectionBy = baseRest(function(arrays) {
32    var iteratee = last(arrays),
33        mapped = arrayMap(arrays, castArrayLikeObject);
34  
35    if (iteratee === last(mapped)) {
36      iteratee = undefined;
37    } else {
38      mapped.pop();
39    }
40    return (mapped.length && mapped[0] === arrays[0])
41      ? baseIntersection(mapped, baseIteratee(iteratee, 2))
42      : [];
43  });
44  
45  module.exports = intersectionBy;