I got:
$(someTextInputField).keypress(function() { alert($(this).val()); });
Now the alert always returns the value BEFORE the keypress (
Surprised that no one mentioned the js "input" event:
$(someTextInputField).on('input', function() { alert($(this).val()); });
Recommended.
https://developer.mozilla.org/en-US/docs/Web/Events/input