JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://rawgit.com/lodash/lodash/530bf7df9f869b7bc030f2936b79ff8799b14db3/lodash.js"></script>

JavaScript

var x = _.map([1, 2, 3], function(n) { return n * 3; });
console.log(x);

var arr1 = [{ 'x': 'a' }];
var arr2 = [
  { 'x': 'b' },
  { 'x': 'c' }
];

console.log(_.spread);
var merge = _.spread_.partial(_.merge, {}));
merge(arr1, arr2);
console.log(arr1);