import size from '../../util/size'

/**
 * A specialized version of `reduce` for arrays.
 * @since 5.0.0-beta.6
 *
 * @param {Array} [array] The array to iterate over.
 * @param {Function} iteratee The function invoked per iteration.
 * @param {*} [accumulator] The initial value.
 * @param {boolean} [initAccum] Specify using the first element of `array` as
 *  the initial value.
 * @return {*} Returns the accumulated value.
 */
function arrayReduce(array, iteratee, accumulator, initAccum) {
  let index = -1
  const length = size(array)

  if (initAccum && length) {
    accumulator = array[++index]
  }
  while (++index < length) {
    accumulator = iteratee(accumulator, array[index], index, array)
  }
  return accumulator
}

export default arrayReduce