Adding comma separated strings to an ArrayList c#

Question

How to add a comma separated string to an ArrayList? My string could hold 1 or many items which I'd like to add to ArrayList, each item combine with it's own id value separated by underscore (_) so it must be separated arraylist items..

eg :

string supplierIdWithProducts = "1_1001,1_1002,20_1003,100_1005,100_1006";

ArrayList myArrayList= new ArrayList();
myArrayList.Add("1001,1002"); // 1
myArrayList.Add("1003"); // 20
myArrayList.Add("1005,1006"); // 100

After the ArrayList has been populated, I'd like pass it to a web service that part is ok for me
foreach (string item in myArrayList){}

How could i do this...

Thanks..

Answer 1

string supplierIdWithProducts = "1_1001,1_1002,20_1003,100_1005,100_1006";

var lookup = 
     supplierIdWithProducts.Split(',')
                           .ToLookup(id => id.Split('_')[0],
                                     id => id.Split('_')[1]);

foreach (var grp in lookup)
{
    Console.WriteLine("{0} - {1}", grp.Key, string.Join(", ", grp));
}

will print:

1 - 1001, 1002
20 - 1003
100 - 1005, 1006

Answer 2

Firstly, I suggest you try to use a Dictionary or any other generic collection instead of an ArrayList to make it type-safe. Then use a string.Split(char c) and start the processing from there.

Here's an idea on how you can do it. It might get shorter with Extension methods of course. But here's just a thought-process on how you can do it.

    static void ParseSupplierIdWithProducts()
    {
        string supplierIdWithProducts = "1_1001,1_1002,20_1003,100_1005,100_1006";

        //eg. [0] = "1_1001", [1] = "1_1002", etc
        List<string> supplierIdAndProductsListSeparatedByUnderscore = supplierIdWithProducts.Split(',').ToList();

        //this will be the placeholder for each product ID with multiple products in them
        //eg. [0] = key:"1", value(s):["1001", "1002"]
        //    [1] = key:"20", value(s):["1003"]
        Dictionary<string, List<string>> supplierIdWithProductsDict = new Dictionary<string, List<string>>();

        foreach (string s in supplierIdAndProductsListSeparatedByUnderscore)
        {
            string key = s.Split('_')[0];
            string value = s.Split('_')[1];

            List<string> val = null;

            //look if the supplier ID is present
            if (supplierIdWithProductsDict.TryGetValue(key, out val))
            {
                if (val == null)
                {
                    //the supplier ID is present but the values are null
                    supplierIdWithProductsDict[key] = new List<string> { value };
                }
                else
                {
                    supplierIdWithProductsDict[key].Add(value);
                }
            }
            else
            {
                //that supplier ID is not present, add it and the value/product
                supplierIdWithProductsDict.Add(key, new List<string> { value });
            }
        }
    }