lodash/internal/mapHas.js

define(['./Map', './assocHas', './hashHas', './isKeyable'], function(Map, assocHas, hashHas, isKeyable) {

  /**
   * Checks if a map value for `key` exists.
   *
   * @private
   * @name has
   * @memberOf MapCache
   * @param {string} key The key of the entry to check.
   * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
   */
  function mapHas(key) {
    var data = this.__data__;
    if (isKeyable(key)) {
      return hashHas(typeof key == 'string' ? data.string : data.hash, key);
    }
    return Map ? data.map.has(key) : assocHas(data.map, key);
  }

  return mapHas;
});