serializeForm

Encodes a set of form elements as a query string.

• Use the FormData constructor to convert the HTML form to FormData.
• Use Array.from() to convert to an array, passing a map function as the second argument.
• Use Array.prototype.map() and encodeURIComponent() to encode each field's value.
• Use Array.prototype.join() with appropriate arguments to produce an appropriate query string.

const serializeForm = form =>
  Array.from(new FormData(form), field =>
    field.map(encodeURIComponent).join('=')
  ).join('&');

serializeForm(document.querySelector('#form'));
// email=test%40email.com&name=Test%20Name