radio button on checked code example

Example 1: jquery radio button checked event

$('input:radio[name="postage"]').change(function(){

        if ($(this).val() == 'Yes') {
            //true
        }
        else {
            //false
        }
    });

Example 2: html radio button checked

<input type="radio" id="huey" name="drone" value="huey"
         checked> 
<!-- https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/radio-->

Example 3: javascript uncheck radio button

document.getElementById("radioButtonID").checked = false; //uncheck a radio button
document.getElementById("radioButtonID").checked = true; //check a radio button

Example 4: which radio button is selected javascript

$('#myForm input').on('change', function() {
   alert($('input[name=radioName]:checked', '#myForm').val()); 
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<form id="myForm">
  <input type="radio" name="radioName" value="1" /> 1 <br />
  <input type="radio" name="radioName" value="2" /> 2 <br />
  <input type="radio" name="radioName" value="3" /> 3 <br />
</form>