HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>mergeWith vs merge</title>
</head>
<body>
  <h1>mergeWith vs merge</h1>
  <pre id="out"></pre>
  <script src="https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js"></script>
  <script>
    var left = { items: [1, 2, 3] };
    var right = { items: [10] };
    document.getElementById("out").textContent =
      JSON.stringify(_.merge({}, left, right)) + "
" +
      JSON.stringify(_.mergeWith({}, left, right, function (o, s) {
        if (_.isArray(o)) return o.concat(s);
      }));
  </script>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

Lodash _.mergeWith vs _.merge (Try It)