In the following code snippet, the String.fromCharCode is used, can all JS methods be used within jQuery?

Perhaps a noob question, but better to ask and prove a noob, then assume and be a fool.

 // Invoke setBodyClass when a key is pressed
$(document).keyup(function(){
    switch (String.fromCharCode(event.keyCode)){
      case 'D':
        setBodyClass('default');
        break;
      case 'N':
        setBodyClass('narrow');
        break;
      case 'L':
        setBodyClass('large');  
        break;
    }

});//end keyup