blob: 324a2b1db2857883ea5a34541c6a5cd6e4819a7a [file] [log] [blame]
var arrayMap = require('../internal/arrayMap'),
arrayReduce = require('../internal/arrayReduce'),
bindCallback = require('../internal/bindCallback'),
unzip = require('./unzip');
/**
* This method is like `_.unzip` except that it accepts an iteratee to specify
* how regrouped values should be combined. The `iteratee` is bound to `thisArg`
* and invoked with four arguments: (accumulator, value, index, group).
*
* @static
* @memberOf _
* @category Array
* @param {Array} array The array of grouped elements to process.
* @param {Function} [iteratee] The function to combine regrouped values.
* @param {*} [thisArg] The `this` binding of `iteratee`.
* @returns {Array} Returns the new array of regrouped elements.
* @example
*
* var zipped = _.zip([1, 2], [10, 20], [100, 200]);
* // => [[1, 10, 100], [2, 20, 200]]
*
* _.unzipWith(zipped, _.add);
* // => [3, 30, 300]
*/
function unzipWith(array, iteratee, thisArg) {
var length = array ? array.length : 0;
if (!length) {
return [];
}
var result = unzip(array);
if (iteratee == null) {
return result;
}
iteratee = bindCallback(iteratee, thisArg, 4);
return arrayMap(result, function(group) {
return arrayReduce(group, iteratee, undefined, true);
});
}
module.exports = unzipWith;