unzip.js 1.25 KB
var arrayFilter = require('./_arrayFilter'),
    arrayMap = require('./_arrayMap'),
    baseProperty = require('./_baseProperty'),
    baseTimes = require('./_baseTimes'),
    isArrayLikeObject = require('./isArrayLikeObject');

/* Built-in method references for those with the same name as other `lodash` methods. */
var nativeMax = Math.max;

/**
 * This method is like `_.zip` except that it accepts an array of grouped
 * elements and creates an array regrouping the elements to their pre-zip
 * configuration.
 *
 * @static
 * @memberOf _
 * @since 1.2.0
 * @category Array
 * @param {Array} array The array of grouped elements to process.
 * @returns {Array} Returns the new array of regrouped elements.
 * @example
 *
 * var zipped = _.zip(['a', 'b'], [1, 2], [true, false]);
 * // => [['a', 1, true], ['b', 2, false]]
 *
 * _.unzip(zipped);
 * // => [['a', 'b'], [1, 2], [true, false]]
 */
function unzip(array) {
  if (!(array && array.length)) {
    return [];
  }
  var length = 0;
  array = arrayFilter(array, function(group) {
    if (isArrayLikeObject(group)) {
      length = nativeMax(group.length, length);
      return true;
    }
  });
  return baseTimes(length, function(index) {
    return arrayMap(array, baseProperty(index));
  });
}

module.exports = unzip;