Getting index of dictionary item based on item.key

Question

How can I find the index of an element of a dictionary based on the element key? I'm using the following code to go through the dictionary:

foreach (var entry in freq)
{
    var word = entry.Key;
    var wordFreq = entry.Value;
    int termIndex = ??????;
}

Could anyone help please?

Answer 1

There is no concept of an index in a Dictionary. You can't rely on any order of items inside the Dictionary. The OrderedDictionary might be an alternative.

var freq = new OrderedDictionary<string, int>();
// ...

foreach (var entry in freq)
{
    var word = entry.Key;
    var wordFreq = entry.Value;
    int termIndex = GetIndex(freq, entry.Key);
}


public int GetIndex(OrderedDictionary<string, object> dictionary, string key) 
{
    for (int index = 0; index < dictionary.Count; index++)
    {
        if (dictionary.Item[index] == dictionary.Item[key]) 
            return index; // We found the item
    }

    return -1;
}

Answer 2

This might work and this is probably not the most efficient way of doing this. Also im not sure why you would want something like this.

Int termIndex = Array.IndexOf(myDictionary.Keys.ToArray(), someKey);