set selected radio button value jquery code example

Example 1: get value of checked radio button jquery

$('form input[type=radio]:checked').val();

Example 2: jquery select specific radio button by value

$("input[name=mygroup][value=" + value + "]").prop('checked', true);

Example 3: change selected radio jquery

Say you had radio buttons like these, for example:

<input type='radio' name='gender' value='Male'>
<input type='radio' name='gender' value='Female'>
  
And you wanted to check the one with a value of "Male" onload if no radio is 
checked:

$(function() {
    var $radios = $('input:radio[name=gender]');
    if($radios.is(':checked') === false) {
        $radios.filter('[value=Male]').prop('checked', true);
    }
});