firing a jQuery change function at document ready

Question

My change function allows users to switch from country to country and get different text and features. It works when changing country selections. But at initial page load, it do

Answer 1

This usually is made as:

function onChange ()
{                                                                               
    switch ($('input[name=country]:checked').val())
    ....
}

$('input[name=country]').change(onChange); // 1. attach it as event handler.
onChange();                                // 2. call it first time.

Answer 2

Just chain .trigger('change') to the end of the handler assignment.

 // ----------v-------v-----quotation marks are mandatory
$('input[name="country"]').change(function ()
{                                                                               
// change user instructions to be country specific
    switch ($('input[name="country"]:checked').val())
    {
        case 'US':
        $('#stateMessage1').text('2. Select a state or territory of the United States.');
        $('#stateMessage2').text('Start typing a state of the United States, then click on it in the dropdown box.');
        $('#threeSelects').show();
        $('#twoSelects').hide();
        //select via 3 steps                        
        break;           
        case 'CA':
        $('#stateMessage1').text('2. Select a province or territory of Canada.');
        $('#stateMessage2').text('Start typing a province of Canada, then click on it in the dropdown box.');
        $('#twoSelects').show();
        $('#threeSelects').hide();
        //select town via 2 steps - country, town           
        break;         
    }
}).trigger('change');  // <--- RIGHT HERE

---

Or if you only want it to fire on the first element, use triggerHandler() instead.

        // ...
        $('#twoSelects').show();
        $('#threeSelects').hide();
        //select town via 2 steps - country, town           
        break;         
    }
}).triggerHandler('change');  // <--- RIGHT HERE

Answer 3

Why not just trigger change after selecting the appropriate radio buttons?

$('input[name=country]').change();

This is equivalent to

$('input[name=country]').trigger('change');

Answer 4

Before the final });, add in $('input').change();