OrderedDictionary and Dictionary

Question

I was looking for a way to have my Dictionary enumerate its KeyValuePair in the same order that they were added. Now, Dictionary\'s documentation c

Answer 1

You are doing it wrong. You need not only to insert values sequentially into dictionary, but also remove some elements and see how the order has changed after this. The next code demonstrates this:

OrderedDictionary od = new OrderedDictionary();
Dictionary<String, String> d = new Dictionary<String, String>();
Random r = new Random();

for (int i = 0; i < 10; i++)
{
    od.Add("key" + i, "value" + i);
    d.Add("key" + i, "value" + i);
    if (i % 3 == 0)
    {
        od.Remove("key" + r.Next(d.Count));
        d.Remove("key" + r.Next(d.Count));
    }
}

System.Console.WriteLine("OrderedDictionary");
foreach (DictionaryEntry de in od) {
    System.Console.WriteLine(de.Key + ", " +de.Value);
}

System.Console.WriteLine("Dictionary");
foreach (var tmp in d) {
    System.Console.WriteLine(tmp.Key + ", " + tmp.Value);
}

prints something similar to (OrderedDictionary is always ordered):

OrderedDictionary
key3, value3
key5, value5
key6, value6
key7, value7
key8, value8
key9, value9
Dictionary
key7, value7
key4, value4
key3, value3
key5, value5
key6, value6
key8, value8
key9, value9