Just to throw another hat in the ring.  Determining characters in keypress events isn't something that JavaScript does very well right now. Due to it's variability, I'd rather not force any method to have to decipher it inline, and defer evaluation to another method that can be subbed in and out.  

The ideal would be a method that takes in the KeyUp [`Event`][KeyUp] as an argument and returns whatever character was pressed: Let's call it `MapKeyPressToActualCharacter`.  

Then your code could look super clean like this:



    $("#id").on("keyup", function(e){
        switch(MapKeyPressToActualCharacter(e)) {
            case "#":
                //handle #
                break;
            case "@":
                //handle @
                break;
        }
    });

Now we just have to figure out how to write `MapKeyPressToActualCharacter`.  
Here's an implementation based off the answer to [get key char from keycode with shift modifier][GetKeyCode]:



    function MapKeyPressToActualCharacter(event) {
        var isShiftKey = event.shiftKey;
        var characterCode = event.keyCode;
        var isAlphabetChar = characterCode >= 65 && characterCode <= 90;
        var specialChars = [8,9,13,16,17,18,20,27,91,92];
        var character = "";
        
        if (valueInArray(characterCode, specialChars)) {
            return false;
        }
    
        if (isAlphabetChar) {
            character = String.fromCharCode(characterCode);
        } else if (isShiftKey) {
            character = GetShiftedCharacters()[characterCode];
        } else {
            character = String.fromCharCode(characterCode);
        }
        return character;
    }
    
    function valueInArray(value, array) {
        return array.indexOf(value) > -1;
    }
    
##[Working Demo in Fiddle][fiddle]

You'll also need to get a mapping of each character and it's shifted corollary with the method `GetShiftedCharacters`:



    function GetShiftedCharacters() {
        var characterMap = {32: " ",
                            48: ")",
                            49: "!",
                            50: "@",
                            51: "#",
                            52: "$",
                            53: "%",
                            54: "^",
                            55: "&",
                            56: "*",
                            57: "(",
                            59: ":",
                            107: "+",
                            109: "_",
                            188: "<",
                            190: ">",
                            191: "?",
                            192: "~",
                            219: "{",
                            220: "|",
                            221: "}",
                            222: "\\" };
        return characterMap;
    }

###Here's a distributable JS file: [**MapKeyPress.js**][MapKeyPress]


*Note, since the MapKeyPress function calls `array.indexOf`, you should use a [polyfill][polyfill] to extend to older browsers.  Here's a shiv called [indexOfPolyFill.js][indexOfPolyFill.js], and here's an [example][indexOf example].

[KeyUp]: https://developer.mozilla.org/en-US/docs/Web/Reference/Events/keyup
[GetKeyCode]: https://stackoverflow.com/a/4786582/1366033
[MapKeyPress]: http://kylemitofsky.com/libraries/libraries/MapKeyPress.js
[fiddle]: http://jsfiddle.net/KyleMit/Bd67a/
[polyfill]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf#Polyfill
[indexOfPolyFill.js]: http://kylemitofsky.com/libraries/libraries/indexOfPolyFill.js
[indexOf example]: http://jsfiddle.net/KyleMit/3VNKQ/

The title pretty much explains it, but I am simply wondering if there is a way to use keyup to tell my code to react to @ but not 2...same with # and 3.

Right now it gives me the same keycode for 2 and @ which leads to some undesirable behavior.

Anyone know the magic?

**UPDATE - SOLVED**

Based on the discussions in the comments below with @RobW and @MonkeyZeus, I have learned that while there are several ways to get what I need, the most straight forward answer is to use keypress rather than keyup. If you must use keyup for some reason, then there are some great solutions to detect the shift key in the other answers below. 

Thanks,
David