| import arrayReduce from './.internal/arrayReduce.js' | |
| import baseEach from './.internal/baseEach.js' | |
| import baseReduce from './.internal/baseReduce.js' | |
| /** | |
| * Reduces `collection` to a value which is the accumulated result of running | |
| * each element in `collection` thru `iteratee`, where each successive | |
| * invocation is supplied the return value of the previous. If `accumulator` | |
| * is not given, the first element of `collection` is used as the initial | |
| * value. The iteratee is invoked with four arguments: | |
| * (accumulator, value, index|key, collection). | |
| * | |
| * Many lodash methods are guarded to work as iteratees for methods like | |
| * `reduce`, `reduceRight`, and `transform`. | |
| * | |
| * The guarded methods are: | |
| * `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, | |
| * and `sortBy` | |
| * | |
| * @since 0.1.0 | |
| * @category Collection | |
| * @param {Array|Object} collection The collection to iterate over. | |
| * @param {Function} iteratee The function invoked per iteration. | |
| * @param {*} [accumulator] The initial value. | |
| * @returns {*} Returns the accumulated value. | |
| * @see reduceRight, transform | |
| * @example | |
| * | |
| * reduce([1, 2], (sum, n) => sum + n, 0) | |
| * // => 3 | |
| * | |
| * reduce({ 'a': 1, 'b': 2, 'c': 1 }, (result, value, key) => { | |
| * (result[value] || (result[value] = [])).push(key) | |
| * return result | |
| * }, {}) | |
| * // => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed) | |
| */ | |
| function reduce(collection, iteratee, accumulator) { | |
| const func = Array.isArray(collection) ? arrayReduce : baseReduce | |
| const initAccum = arguments.length < 3 | |
| return func(collection, iteratee, accumulator, initAccum, baseEach) | |
| } | |
| export default reduce |
