zip-2.js

'use strict';

Array.prototype.zip = function(left, right, combinerFunction) {
  let results, length;

  length = Math.min(left.length, right.length);
	results = [];
  for (let i = 0; i < length; i++) {
    results.push(combinerFunction(left[i], right[i]));
  }

  return results;
}

console.log([].zip([1, 2], [1, 2, 3], function(l, r) {
	return l + r; 
})); // [2, 4]