Using $('input[name="radioName"]').filter(":checked").val(); is the best way for me.

Tested, this works

Form

<form id="myForm">
  <input type="radio" name="radioName" value="Option1"> Option1
  <input type="radio" name="radioName" value="Option2" checked> Option2
  <input type="radio" name="radioName" value="Option3"> Option3
</form>

Jquery

$(document).ready(function() {
  $('input[name="radioName"]').on('change', function() {
     const val = $(this).filter(":checked").val();
     alert(val);
  })

  // First load check
  const val = $('input[name="radioName"]').filter(":checked").val();
  alert(val);
});

Example here: https://codepen.io/BenKennish/pen/GRdRRg

Using $('input[name="radioName"]').filter(":checked").val(); is the best way for me.

Tested, this works

Form

<form id="myForm">
  <input type="radio" name="radioName" value="Option1"> Option1
  <input type="radio" name="radioName" value="Option2" checked> Option2
  <input type="radio" name="radioName" value="Option3"> Option3
</form>

Jquery

$(document).ready(function() {
  $('input[name="radioName"]').on('change', function() {
     const val = $(this).filter(":checked").val();
     alert(val);
  })

  // First load check
  const val = $('input[name="radioName"]').filter(":checked").val();
  alert(val);
});

Example here: https://codepen.io/abinhho/pen/mdLrqbX