Get Dictionary key by using the dictionary value

public static class Extensions
{
    public static bool TryGetKey<K, V>(this IDictionary<K, V> instance, V value, out K key)
    {
        foreach (var entry in instance)
        {
            if (!entry.Value.Equals(value))
            {
                continue;
            }
            key = entry.Key;
            return true;
        }
        key = default(K);
        return false;
    }
}

the usage is also so simple

int key = 0;
if (myDictionary.TryGetKey("twitter", out key))
{
    // successfully got the key :)
}

Link : http://stackoverflow.com/questions/4001908/get-dictionary-key-by-using-the-dictionary-value

[참조] https://www.dotnetperls.com/extension