name : intersectionBy.js var arrayMap = require('./_arrayMap'), baseIntersection = require('./_baseIntersection'), baseIteratee = require('./_baseIteratee'), baseRest = require('./_baseRest'), castArrayLikeObject = require('./_castArrayLikeObject'), last = require('./last'); /** * This method is like `_.intersection` except that it accepts `iteratee` * which is invoked for each element of each `arrays` to generate the criterion * by which they're compared. The order and references of result values are * determined by the first array. The iteratee is invoked with one argument: * (value). * * @static * @memberOf _ * @since 4.0.0 * @category Array * @param {...Array} [arrays] The arrays to inspect. * @param {Function} [iteratee=_.identity] The iteratee invoked per element. * @returns {Array} Returns the new array of intersecting values. * @example * * _.intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor); * // => [2.1] * * // The `_.property` iteratee shorthand. * _.intersectionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x'); * // => [{ 'x': 1 }] */ var intersectionBy = baseRest(function(arrays) { var iteratee = last(arrays), mapped = arrayMap(arrays, castArrayLikeObject); if (iteratee === last(mapped)) { iteratee = undefined; } else { mapped.pop(); } return (mapped.length && mapped[0] === arrays[0]) ? baseIntersection(mapped, baseIteratee(iteratee, 2)) : []; }); module.exports = intersectionBy;