jQuery After page loaded, check if radio button selected

Question 1

Try with:

$(document).ready(function(){
    $("input[type=radio][name='q22']:checked").val()
});

Question 2

Your code is ok.

What you might have forgoten is to run it after page has loaded and the html has been read. You can use jQuery's .ready() to do this.

$(document).ready(function () {
    var i = $("input[type=radio][name=q22]:checked").val();
    console.log(i);
});

Demo here

Question 3

Either just put your script at the bottom of the page, just before the closing </body> tag, or use jQuery's ready event. In either case, the script will have access to the elements on the page and can get the value of the checked radio button.

Gratuitous live example | source

Question 4

used $(document).ready(handler)

Specify a function to execute when the DOM is fully loaded.

Check This

$(document).ready(function() {
    // Handler for .ready() called.
    // Code run after DOM load success 
});


<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
  alert("")
});
</script>
</head>
<body>
</body>
</html>

it will alert after BODY loaded success

Question 5

try

var arr=$("input[type=radio][name=q22]:checked").map(function(){return $(this).val();})

Question 6

Try this :

$(function(){
    $("input[type=radio][name='q22']:checked").val();
});

or else you can also use this :

    $(function(){
       if ($("#radio1").is(":checked")) {
         // do something
       }
    });