Correct way to index a small collection of values

Question

What is the best way to do something like the following where an id is passed to a method. Is a case statement ok or some sort of collection like a hashtable better?

private string GetCurrencySymbol(string code)
    {
        switch (code)
        {
            case "USD":
            case "AUD":
            case "CAD":
            case "NAD":
            case "NZD":
            case "SGD":
            case "HKD":
                return "$";
            case "GBP":
                return "£";
            case "NOK":
            case "DKK":
            case "SEK":
                return "kr";
            case "ZAR":
                return "R";
            case "JPY":
                return "¥";
            case "CHF":
                return "CHF";
            case "EUR":
                return "€";
            case "GHS":
                return "¢";
            case "BWP":
                return "P";
            case "INR":
                return "₹";
            case "KES":
                return "KSh";
            case "LSL":
                return "L";
            case "MUR":
                return "Rs";
            case "NGN":
                return "₦";
            case "MWK":
                return "MK";
            case "MZM":
                return "MT";
            case "PKR":
                return "Rs";
            case "PLN":
                return "zł";
            case "SZL":
                return "L";
            case "TZS":
                return "Sh";
            case "UGX":
                return "Sh";
            case "ZMK":
                return "ZK";
            default:
                return "";
        }
    }

This seems to smell a bit? It's not accessed all that often but seems a bit verbose.

Answer 1

A switch statement will end up being translated into a Dictionary eventually. It often makes sense on more complex examples (such as this one) to go straight to that.

Dictionary<string, string> currencyLookup = new Dictionary<string, string>();
currencyLookup["USD"] = "$";
//...

string currency = currencyLookup["INR"];

Some of the advantages of using a dictionary:

1. It can require a tad less code if you want to define all of the options as literals. (Particularly if using collection initializers.)
2. You can populate the dictionary based on information in a file, from a database, or some other external source so that you don't need to define all of the mappings in code. In addition to making the code cleaner, this let you add/remove/change currencies without needing to re-compile your program.
3. You have access to operations such as ContainsKey to know whether or not a particular key exists, as opposed to just returning an empty string if it's not found (which you can still do as well).

Answer 2

The case statement is perfect in your case.