1  /**
 2   * A specialized version of `_.reduce` for arrays without support for
 3   * iteratee shorthands.
 4   *
 5   * @private
 6   * @param {Array} [array] The array to iterate over.
 7   * @param {Function} iteratee The function invoked per iteration.
 8   * @param {*} [accumulator] The initial value.
 9   * @param {boolean} [initAccum] Specify using the first element of `array` as
10   *  the initial value.
11   * @returns {*} Returns the accumulated value.
12   */
13  function arrayReduce(array, iteratee, accumulator, initAccum) {
14    var index = -1,
15        length = array == null ? 0 : array.length;
16  
17    if (initAccum && length) {
18      accumulator = array[++index];
19    }
20    while (++index < length) {
21      accumulator = iteratee(accumulator, array[index], index, array);
22    }
23    return accumulator;
24  }
25  
26  module.exports = arrayReduce;