JSFiddle - React, Tailwind, and code Playground

HTML

<form action="" id="myform">
  <input type="text" title="foo">
  <input type="text" title="bar">
</form>

JavaScript

$('#myform input').each(function(){
  var $input = $(this)
  var title = $input.attr('title')
  $input.attr('placeholder', title)
})