jquery invoke .change without user action but by .val change

Question

I have a form with a text box that has its value changed from a function. How would I create a function based on the value changing from the script and not the user \"clicking\"

Answer 1

You will need to call the change yourself in the code which updates the value:

$('#ShippingCost').val("something")
                  .change();  // this will execute the change code

Changing values through javascript does not fire events.

Answer 2

I'd just blur the input, so the change triggers on its own.

$('#ShippingCost').val('changed value').blur();

Answer 3

You need to trigger the event manually:

$('#ShippingCost').trigger('change');