como set checked in radio input jquery code example

Example 1: jquery set radio button value

$('#' + newcol).prop('checked',true);

Example 2: 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);
    }
});