javascript - How to submit a form and then, redirect the user to a different page, previously selected on the form?

I'm trying to find a way to submit a form and then, redirect the user to a different page, previously selected on the form. How can I do it? (I'm using PHP to execute the form)

This is my current code.

<select data-select-name id="select-45ba" name="select" class="u-border-1 u-border-grey-30 u-input u-input-rectangle u-radius-50 u-white u-input-15">
  <option value="QTD">QTD</option>
  <option value="page.com">1 - R$32</option>
  <option value="page.com">2 - R$64</option>
  <option value="page.com">3 - R$96</option>
  <option value="page.com">4 - R$128</option>
  <option value="page.com">5 - R$160</option>
</select>

<script type="text/javascript">
  document.addEventListener('DOMContentLoaded', function() {
    document.querySelector('select[data-select-name]').onchange = changeEventHandler;
  }, false);

  function changeEventHandler(event) {
    window.location.href = this.options[this.selectedIndex].value;
  }
</script>

Solution:

Your PHP code will look like this:

header( $header, $replace, $http_response_code );

See

https://code.tutsplus.com/tutorials/how-to-redirect-with-php--cms-34680

However, this is only needed if you absolutely want to send a request to the server after all for some reason before redirecting. An alternative approach would be to redirect from the client-side, by adding the

onchange="yourfunction(this);"

property to your select tag and implement it like

function yourfunction(element) {
    window.location.href = element.value;
}