JSFiddle - React, Tailwind, and code Playground

by refan

HTML

<script src="https://code.jquery.com/jquery-2.2.1.js"></script>
Country Seclect:
<select name="input_15" id="input_1_15" class="medium gfield_select" tabindex="2">
  <option data-cur="JPY" value="Nhật Bản">Nhật Bản</option>
  <option data-cur="USD" value="Anh">Anh</option>
  <option value="Canada">Canada</option>
  <option value="Đức">Đức</option>
  <option value="Pháp">Pháp</option>
  <option value="Hàn Quốc">Hàn Quốc</option>
  <option value="Mỹ">Mỹ</option>
  <option value="Nga">Nga</option>
  <option value="Singapore">Singapore</option>
  <option value="Ý">Ý</option>
  <option value="Thái Lan">Thái Lan</option>
</select>

Curreny select:
<select name="input_16" id="input_1_16" class="medium gfield_select" tabindex="10">
  <option value="JPY">JPY</option>
  <option value="USD">USD</option>
  <option value="EUR">EUR</option>
  <option value="CAD">CAD</option>
  <option value="GBP">GBP</option>
  <option value="KRW">KRW</option>
  <option value="RUB">RUB</option>
  <option value="SGD">SGD</option>
  <option value="THB">THB</option>
</select>

JavaScript

jQuery("#input_1_15").change(function() {

  var selectedCurrency = $(this).find(":selected").data("cur");
  $("#input_1_16").val(selectedCurrency);
  
  //var selector = '#input_1_16 option[value="' + selectedCurrency + '"]';
  //$(selector).prop('selected', true);
});