Getting the value of the selected radio field using jQuery isn’t tough. To get the selected radio field value we can use the following code, replacing the name radio_input with your own

<script>
    var selected_radio_value = $("input[name='radio_input']:checked").val();
</script>

We have used the radio name, because logically each radio in a group won’t have the same ID. However, it can also be retrieved with a class name.

<script>
    var selected_radio_value = $(".my_radio_input:checked").val();
</script>

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To get the radio button value when it changes, you can bind to the jQuery change event

<script>
$("input[name='radio_input']").on('change', function(){
    var selected_radio = $("input[name='radio_input']:checked").val();
    if (selected_radio == 'hello_world'){
        // do something
    }
});
</script>

Find some more examples on https://api.jquery.com/radio-selector/.